SERP

The Kelty Cosmic Synthetic 20 combines a cozy synthetic sleeping bag with a lightweight design for backcountry camping. Our testing reveals how this bag keeps you warm while minimizing weight and bulk.

As an Amazon Affiliate™ I may earn from qualifying purchases!

Reviews

Kelty Cosmic Regular Sleeping Bag

When temperatures drop, this sleeping bag keeps you cozy without sacrificing space. The warm down insulation and insulated hood make chilly mornings a thing of the past, while the roomy design lets you stretch out fully.

Kelty Women's Cosmic Synthetic 20

This comfy carrier has room for little ones up to 35 pounds, while keeping mum warm with its 25° F comfort rating. The synthetic fill keeps things light and dry, which is a big win for weekend adventures. With plenty of positive feedback from users heading out on hikes and park walks, it's clear this carrier helps make parenting a whole lot easier.

Kelty VariCom Complete AFSOC System USA

The Kelty VariCom system packs serious cold weather capabilities into a surprisingly versatile sleeping solution. At just over 9 pounds for the regular size, it carries lighter than many comparable systems while offering a generous temperature range from 30° to -50°F. The included Delta and Gamma bags, with their water-resistant nylon shells and Climashield insulation, provide essential protection for both temperate and arctic conditions, while the compact bivy sack keeps things dry and bug-free.

Kelty Supernova 0 Sleeping Bag

This long-distance backpacking sleeping bag combines RDS certified down insulation with synthetic alternatives for reliable warmth in various conditions. The 81-inch length caters to tall sleepers, while the generous 34-inch width promotes comfortable rest. The zipper closure and right-hand orientation accommodate most sleep positions, with the included stuff sack streamlining transport and storage.

Kelty Cosmic Synthetic 20 Degree Sleeping Bag

This cozy synthetic bag keeps you warm down to 20 degrees, perfect for early spring hikes or autumn camping trips. The regular size fits most adults who need that extra warmth without the bulk. While we're talking camping gear, why not check out some great backpacks and tents while you're at it?

Kelty Cosmic Mummy Sleeping Pad

At just 2 pounds and 1 ounce, this self-inflating sleeping pad packs surprisingly well for how comfortable it is. The open-cell foam construction provides a good balance of cushioning and responsiveness, inflating quickly enough to be practical for solo backpackers. The included stuff sack makes it easy to carry around camp, while the single brass valve streamlines the inflation and deflation process.

Kelty Galactic Si Sleeping Pad

With its generous 78" length and 2.5" of open-cell foam cushioning, the Kelty Galactic SI Sleeping Pad offers unparalleled comfort for its weight class. The self-inflating design makes setting up camp a breeze—just open the dual brass valves and let nature do the work. While it excels for car camping and weekend getaways, some users suggest it might be too bulky for backpacking trips.

Kelty Supernova 40 Degree 550 Down Sleeping Bag

The Kelty Supernova 40 degree sleeping bag combines premium recycled materials with 550-fill down insulation for exceptional warmth without the bulk. Its semi-rectangular shape and roomy design accommodate various body types and sleep positions, while features like PFC-free DWR treatment and an anti-snag zipper ensure comfortable nights under the stars. Whether you're camping in your backyard or backpacking in the wilderness, this lightweight bag delivers the cozy sleep you deserve.

Kelty Cosmic 40 Degree Synthetic Sleeping Bag

Featuring insulated synthetic fibers and a water-repellent exterior, this budget-friendly sleeping bag packs down small enough for backpacking while keeping you cozy with its draft tubes and insulated hood. The generous 6-foot footprint and natural-fit footbox give you plenty of room to stretch out, making those chilly summer nights more comfortable than you might expect.

Kelty Cosmic Synthetic 20 Degree Sleeping Bag

This women's sleeping bag strikes a great balance between warmth and weight, thanks to its synthetic insulation that keeps you cozy down to 25°F while staying surprisingly light at just 3.75 lbs. The premium 380T nylon shell and PFC-free water-repellent coating protect your investment, while thoughtful features like the insulated hood and draft tubes make those cold mornings more comfortable. Whether you're a solo traveler or a family camping with kids, the generous 5'8" length and natural-fit footbox ensure everyone finds a comfy spot.

Kelty Mistral 20 Sleeping Bag

The Kelty Mistral 20 offers decent warmth for its rating but struggles in temperatures below 50 degrees, requiring extra layers for comfort. With synthetic insulation and a mummy shape, it provides adequate cocooning with its natural fit footbox and comfort hood, though some might find it slightly bulky for backpacking. Reviews praise its light weight and packability, making it a reasonable choice for budget-conscious campers and casual backpackers.

Kelty Cosmic Down 20 Sleeping Bag

The Kelty Cosmic Down 20 sleeping bag marries exceptional warmth with remarkable lightness, thanks to its premium 550-fill down insulation. The trapezoidal baffling and thoughtful design details like the full draft collar keep you cozy down to 20°F, while the buttery-soft recycled fabrics and PFAS-free DWR coating ensure lasting comfort. Whether you're a light sleeper who gets cold or just prefer the weight savings of down, this bag delivers impressive performance for its category.

Kelty Cosmic 0 Synthetic Sleeping Bag

The Kelty Cosmic 0 Degree sleeping bag combines synthetic insulation with a mummy shape for warmth without the bulk. It performed exceptionally well in cold conditions, with users reporting comfort down to freezing temperatures and even in the teens. At just over 4 pounds, it's surprisingly light while maintaining excellent thermal properties, though some noted it's a bit bulky for backpacking. Overall, it provides a great balance of warmth, comfort, and value for money.

Kelty Supernova 20 Sleeping Bag

This comfortable 20-degree bag combines recycled down insulation with a semi-rectangular shape for enhanced warmth retention. The DWR-coated shell keeps the down dry in damp conditions, while the right-zip design lets you adjust ventilation as the temperature changes. When the weather warms up, you can unzip it completely for use as a cozy blanket around the campfire.

Kelty Cosmic 40 Degree Down Sleeping Bag

At just 1.9 pounds, this highly-rated down sleeping bag packs surprisingly effective warmth for spring and early fall camping. The 550-fill down and well-insulated draft tubes keep you cozy through 40-degree nights, while the buttery-soft shell and roomy mummy design make for comfortable relaxation under the stars. The right-hand zipper and clever features like the phone pocket and internal stash pouch combine practicality with genuine outdoor spirit.

Kelty Tru.Comfort Doublewide 20 Sleeping Bag

The Kelty Tru. Comfort Doublewide 20 combines generous space for two with flexible temperature control through its Comfort-Tuck Zipper System and built-in blankets. Insulated with Kelty's synthetic CloudLoft material that maintains its warmth even when wet, the sleeping bag features a roomy design with an oversized hood that accommodates standard pillows and allows both users to adjust their comfort independently.

Kelty Cosmic Ultra 0 Down Sleeping Bag

The Kelty Cosmic Ultra 0 combines premium 800-fill DriDown insulation with a lightweight 20D nylon shell to create an exceptionally warm yet packable mummy bag. Its innovative trapezoidal baffles enhance thermal efficiency while allowing plenty of room for movement. The bag includes thoughtful features like a zippered stash pocket and DWR-treated fabrics that keep moisture at bay.

Kelty Cosmic Sleeping Pad

The Kelty Cosmic Air Mummy Pad combines ultralight construction with efficient inflation for minimalist backpackers. At just 16 ounces, the pad packs down incredibly small – roughly the size of your typical paperback book when compressed into its included stuff sack. The 20D nylon exterior is TPU laminated for added durability without extra weight, though it does make a slight rustling noise when shifting positions. The integrated inflation valve makes quick work of filling the pad, and its tapered design keeps weight to a minimum while maintaining a comfy sleeping surface.

Kelty Mistral Si Sleeping Pad

After testing the Kelty Mistral Si Sleeping Pad for over a month, I can say it's a decent budget-friendly option for car camping. The self-inflating mummy-style pad keeps you warm with an R-value of 4.7, though some might find it too bulky for backpacking. While the single-valve inflation can be a bit fussy, its lightweight vinyl-coated polyester construction and 1.5-inch thickness make for a reasonably comfortable night in the great outdoors.

Kelty Cosmic 20 Down Sleeping Bag

The Kelty Women's Cosmic Down 20 sleeps surprisingly comfortably for its temp rating, though I did notice some cold spots in the hip area when laying on it. At just 3 pounds, it packs incredibly small and has performed well in all my winter camping trips so far. The mummy shape and women-specific construction really help keep you warm, even when you lose a few feathers over time.

Kelty Cosmic 40 Degree Sleeping Bag

The Kelty Cosmic 40 provides surprisingly good warmth for its weight, though some might find it a bit snug. The down insulation keeps things light and compressible, while thoughtful touches like the external zipper and cozy hood help maintain that 40-degree warmth rating. The long version offers generous length for extended legs, though the slim profile might feel confining for those with broader builds.

Kelty Women's Cosmic Ultra 20 Sleeping Bag

The women's-specific design takes the original Cosmic Bag to new heights of comfort, with a narrower fit through the shoulders and wider hips that help retain heat better than a standard men's bag. The 800-fill DriDown insulation packs light at just 3 pounds while keeping temperatures cozy up to 25 degrees Fahrenheit in cooler conditions. When the temperature drops, the trapezoidal baffle construction helps trap your body heat, keeping you warm without adding extra bulk.

Kelty Mistral 40 Sleeping Bag

The Kelty Mistral 40 balances warmth and packability with its synthetic CloudLoft insulation and 190T polyester construction. The mummy shape maximizes warmth while the full-length zipper and generous 6-foot length accommodate most builds comfortably. The 40-degree temperature rating proves reliable down to unexpectedly cold nights, as one user reported staying warm in 37-degree weather with minimal layers.

Kelty Cosmic 40 DriDown Sleeping Bag Regular

This Kelty Cosmic 40 sleeping bag nails the balance of warmth and weight, clocking in at just 10.2 ounces while keeping you snuggled up to 20 degrees. The DriDown insulation might need an extra day to puff back up after compressing, but once it does, the 600-fill power keeps you cozy without adding bulk. The smart design details like the head stash pocket and dual-slider zipper make it practical for both weekend trips and longer excursions.

Kelty Cosmic Down 20

This warm and well-made down sleeping bag hits the sweet spot for budget-minded campers who don't want to break the bank. With 550-fill duck down and a 20-degree temperature rating, it keeps you cozy down to chilly spring nights. While it's a bit heavy at 2.9 pounds compared to synthetic options, the recycled materials and responsible collection methods make it an eco-friendly choice for your next outdoor adventure.

Kelty Mistral 30 sleeping bag

This Kelty Mistral sleeping bag has become a family favorite for camping trips. The generous 30-degree temperature rating and cozy Cloudloft insulation keep kids comfortable on cool nights, while the roomy mummy shape and natural footbox promote better sleep. Parents appreciate the bag's durability, ease of use, and the included stuff sack for hassle-free storage.

Kelty Cosmic Ultra 20 Degree DriDown Sleeping Bag

Featuring 800-fill DriDown insulation with innovative trapezoidal baffles, the Kelty Cosmic Ultra 20 Degree sleeping bag delivers exceptional warmth while maintaining remarkable packability. The premium 20D nylon shell and liner, combined with C0 and PFC-free DWR treatment, ensure both durability and environmental responsibility. Users appreciate its comfortable forward-leaning footbox, draft tube, and generous 40-inch shoulder circumference, though some note minor cold spots in the knee area.

Kelty Mistral Kids 20 Degree sleeping bag

This well-made sleeping bag keeps kids warm down to 20° F with its synthetic insulation and durable polyester shell. The roomy mummy shape has a detachable footbox and draft tube to block cold air, while the compact size packs easily into the included stuff sack. Built to last with simple care requirements, it's a practical choice that matches its advertised temperature rating when properly zipped up.

Kelty Kush Queen Air Bed with Battery-Powered Pump

This king-sized airbed delivers remarkable comfort for overnight stays, featuring 6-inch thick TPU-laminated construction that isolates you from the ground. The included battery-powered pump inflates the mattress in about 5 minutes, while the carry bag makes it simple to transport. While the thick padding makes it ideal for car camping and indoor use, its substantial weight means it's not suited for backpacking trips.

Kelty Galactic 30 Sleeping Bag

Featuring 550-fill down insulation and a generous 67.5-inch hip girth, the Kelty Galactic 30 Sleeping Bag delivers surprisingly warm comfort for its lightweight design. The roomy rectangular shape allows for natural sleep positioning, while the innovative baffling system minimizes cold spots. Whether you're car camping or backpacking, this highly-rated sleeping bag strikes an impressive balance between warmth, packability, and durability.

Klymit 20F Synthetic Sleeping Bag

The Klymit 20° Synthetic Sleeping Bag delivers comfortable three-season warmth with its pillowy synthetic fill, while the durable water-repellent treatment keeps moisture at bay. The innovative stretch baffles let you move freely without unzipping, though some users might find the bag bulky when compressed. The shoulder room and 78-inch fit accommodate most sleepers, making it a versatile choice for both new and experienced campers.

Kelty Fairbank Backpack

From its 29-liter capacity to its vintage-inspired design, every detail of this backpack feels thoughtfully considered. The padded back panel and adjustable straps ensure comfy carries, while the clever storage solutions—like those hidden water bottle pockets—show off the same practical-mindedness that makes vintage packs so beloved. Whether you're traipsing through the woods or just running errands around town, this Kelty pack nails the balance of old-school charm and modern functionality.

Kelty Cosmic 0 Degree Sleeping Bag

When you're backpacking in cold weather, every ounce matters. The Kelty Cosmic 0 Degree sleeping bag packs down super small but still keeps you warm with its down insulation. It's got some really thoughtful touches like a draft tube and insulated hood to keep the cold out. Overall, it's a solid choice for winter camping when you want something that works reliably without breaking the bank.

Buyer's Guide

The Kelty Cosmic Synthetic 20 is a popular backpacking tent that combines lightweight materials with synthetic insulation for efficient warmth retention. This guide helps you understand the key features and consider what might make it a good fit for your camping needs.

Materials and Construction

The tent's rainfly uses a durable waterproof-breathable nylon construction, while the main body consists of 600D polyester. The synthetic insulation adds significant warmth without the weight of traditional down. The poles are made from durable aluminum, providing good support while keeping the overall weight low.

Design and Layout

The Cosmic Synthetic 20 features a 20-quart groundsheet, ideal for keeping your gear organized and dry. The tent offers single vestibule storage, which helps maintain a clean living space by separating gear from living area. With a footprint of approximately 7 x 7 feet, it provides generous interior space for most backpacking needs.

Setup and Features

The pole system attaches directly to the rainfly, simplifying setup and reducing the number of components. Essential features include a center guyline system for added stability and a roll-top door design that prevents cold air from entering. The tent also includes aluminum guy wires and silicone booties for the poles.

Weight and Portability

The Cosmic Synthetic 20 typically weighs around 2.6 pounds, making it suitable for most backpacking trips where minimizing weight is important. For context, the tent adds about 0.9 pounds compared to the synthetic-only version, while the down version would weigh approximately 2.4 pounds.

FAQ

What is the Kelty Cosmic Synthetic 20?

The Kelty Cosmic Synthetic 20 is a lightweight sleeping bag designed for backpacking and camping, featuring a synthetic insulation core rated to 20°F (-6°C). The bag combines warmth retention with packability for outdoor adventures in cooler climates.

Developed for backcountry enthusiasts, it offers a balance between weight, warmth, and compression, making it suitable for overnight trips where space and weight are premium considerations.

What makes the Cosmic Synthetic different from other Kelty sleeping bags?

The Cosmic Synthetic incorporates specialized insulation that remains effective when wet, unlike down alternatives. Its construction includes Kelty's AirFit comfort system, which enhances breathability and reduces moisture accumulation.

The bag also features a unique, asymmetrical design that allows users to unzip the foot section while keeping the upper body warm, optimizing comfort in various sleeping positions.

How does the Cosmic Synthetic compare to similar bags in its weight class?

At approximately 2 lbs 12 oz (615g), the Cosmic Synthetic ranks among the lightest synthetic-insulated sleeping bags available. It achieves this weight reduction by utilizing high-quality insulation and a minimalist design without compromising essential features.

Compared to similarly rated synthetic bags, the Kelty model typically weighs 15-20% less, making it particularly appealing to ultralight backpackers who prioritize every ounce of their gear.

Can the Cosmic Synthetic be used in colder temperatures than its 20°F rating suggests?

While officially rated to 20°F (-6°C), some users have successfully used this bag in colder conditions. The synthetic insulation performs well down to around 15°F (-9°C), though using a liner or sleeping pad to maintain body heat is recommended for significantly cooler temperatures.

For sub-freezing conditions, particularly in damp or windy environments, users should consider a rated bag for -20°F (-29°C) or colder to ensure adequate warmth.

How compressible is the Cosmic Synthetic?

The bag's synthetic insulation compresses exceptionally well, fitting into its included stuff sack down to a small 8x15-inch package. This allows for easy storage and packing without taking up valuable backpack space.

The compression feature makes it ideal for backpacking trips where minimizing pack weight and volume is crucial, particularly when combining multiple sleeping bags or camping in close quarters.

What maintenance needs does the Cosmic Synthetic require?

Care for the Cosmic Synthetic is minimal. The synthetic insulation can be machine washed in cold water using a mild detergent, though avoiding bleach and harsh chemicals is recommended. After washing, the bag should be air-dried instead of being put in the dryer.

Regular care includes checking the stitching and webbing for signs of wear, and ensuring the zipper operates smoothly. Like any sleeping bag, proper storage in a cool, dry place between uses extends its lifespan.