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Mammut Relax Fiber Bag -2C review: a comfortable and versatile sleeping bag for casual camping

A fairly technical but whimsical sleeping bag, the Mammut Relax Fiber Bag -2C performs well in a range of situations

Mammut Relax Fiber Bag -2C
(Image: © Mammut)

Our Verdict

Supremely comfortable and very versatile, the laid-back Relax sleeping bag makes bedtime a pleasure during casual camping forays and road trips.


  • Very user friendly
  • Women’s specific version available
  • Ajungilak fiber filling impervious to moisture


  • Not as well suited for big backcountry adventures as some other bags

Mammut Relax Fiber Bag -2C: first impressions

Essentially a fair-weather sleeping bag, the fun and funky Mammut Relax Fiber Bag -2C is made for warm summer nights boondocking in a camper van and chilling by the campfire.

The fit of this bag is comfort-focused. A central zipper makes it easy to get in and out of and allows for on-the-fly temperature regulation (see: Sleeping bag temperature ranges explained). The synthetic hydrophobic lining and filling won’t absorb moisture, and the iridescent outer fabric and T-shirt soft shoulder and neck lining aren’t crinkly and loud (thankfully).

Mammut have designed a new anatomical footbox for this bag, to give sleepers more space without adding extra weight (see: Types of sleeping bag). They also added a modest draft tube to keep the cold out. The 100% polyester bag is bluesign approved, with a PVC-free durable water repellent. It’s Fair Wear certified and as a brand Mammut strives to ensure fair and safe working conditions in all factories making its products.


RRP: $200 (US) / £170 (UK)
Weight: 720g / 1lb 9oz
Length: 205cm / 80.7in
Max user height: 172cm / 68in
Packsize: 27 x 22.5cm / 10.6 x 8.86in
Fill: Mammut’s synthetic Ajungilak 100% Polyester insulation
Comfort: 3°C / 37°F
Limit: -2°C  / 28°F
Compatibility: 2 to 3-season

In the field

The anarchic purple and pink design of this bag (I tested the women’s version – see: Best women’s sleeping bags) is not just eye-catching, I also found it to be spacious and comfortable, and it quickly became my go-to user-friendly bag for use camping at my favorite surf break, and couch surfing on a cross-country road trips.

The recycled-content synthetic fill bag has a full-length zipper. As a result I could unzip from the bottom when I wanted to wander but didn’t want to get out of my bag, which was at home around the campfire as well as in the tent.

Where a lot of bags seem too technical for impromptu summer outings, this one always fits right in. The T-shirt-soft material around the neck was cozy, not crinkly. A snap at the top of the zipper didn’t get caught in my hair as Velcro tabs on most bags do. And the stash pocket not only held my headlamp, but a paperback, my wallet, and my phone too.

This might not be the bag for scaling Everest, but it is the bag to keep in the back of the car for anytime adventures.