$289.00 – $309.00  | #22400  | Updated

The Atom’s ultra-light design and our highest quality down have given it cult status among alpinists as a bivvy bag on extreme climbs, but its comfortable, silky fabric make it a great bag for warm-weather bivvies on casual summer road trips as well. Updated with our Down Defender treatment offering an extra level of moisture protection for sleeping bags exposed to wet environments.

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Feature List
Certified 850+ Fill Power Goose Down, Classic Trapezoidal Foot Box, Down Defender to Improve Water-Resistance in Wet Conditions, EN Tested, Full Length Zipper, Hood Draw Cord, Insulated Draft Tube, Nautilus 6-Baffle Hood, Pertex Microlight Shell and Lining Fabric, Sewn-Through Baffles, Stretch Tricot Baffles at Hood and Foot Box, Stuff and Storage Sack Included, Velcro -free Face Muff, Zipper Garage, Zipper Guards
Main Materials
20 Denier 100% Nylon Ripstop DWR 1.2 oz/yd
1lbs 8oz (680g)
Fill Weight
10oz (283g)
Bag Temperature F
40° F
Bag Temperature C
4° C
EN Rating
Comfort: 50.5°F / 10.3°C | Lower Limit: 43.2°F / 6.2°C | Extreme: 18.6°F / -7.4°C
Bag Loft
Bag Zipper position
Lining Material
30 Denier 100% Nylon 1.3 oz/yd
Insulation Material
850+ Fill Power Goose Down


Down Defender

What is it ?

Marmot Down Defender is an insurance policy for your down products. This specially treated highly water-resistant down offers an extra level of moisture protection for down exposed to wet environments. Down Defender helps prevent down from clumping and losing its loft when exposed to water, thereby greatly increasing its ability to keep you warm and comfortable.

  • Stays drier 10 times longer than untreated down
  • Maintains 150% more loft than untreated down in damp conditions
  • Dries 30% faster than untreated down
  • Treatment is PFOA and PFOS free
  • Bluesign approved

How does it work ?

The treatment coats the individual plumes of the down cluster with a DWR (durable water repellent) at the molecular level. It puts a hydrophobic layer on each individual plume of the cluster. This treatment is done during the down cleaning process. The finish is extremely durable allowing the down to maintain its water repellency over 20 washes. The treatment also enhances the down's integrity and the durability of the cluster helping to increase its longevity.

What are the benefits of this technology?

Down Defender products stay drier longer, maintain their loft better and dry faster than conventional untreated down products.

Wash & Care

Why do we encourage proper care of our clothing and gear?

Because you have invested in (or are thinking about investing in) one of the most technically advanced pieces of apparel or equipment you'll ever own and we want to make sure you have the information you need to protect and care for your purchase. Proper care assures you will optimize the performance of your Marmot product and maximize its service-life.

Sleeping Bag Care

  • Hand wash warm, 105 degrees Fahrenheit or 40 degrees Celsius or machine wash Warm, Gentle cycle in a front load washer only.
  • If you need to use a detergent, only use powdered form
  • Rinse thoroughly
  • Do not wring your sleeping bag
  • Hang dry or tumble dry on low heat. If tumble drying a down bag, toss a couple of clean tennis balls in the dryer to help re-loft the bag
  • After your bag is dry, store in a loose storage container. Cotton or mesh stuff sacks or extra-large pillow cases work well
  • Do not store in a space where temperatures could exceed 125 degree Fahrenheit
  • Do not bleach
  • Do not iron
  • Do not dry clean