Our review of the Mammut Perform Down Bag

The Mammut Perform Down Bag takes a different approach to the other bags with a full-length centre zip for access.

I like the options this entry format presents to you; it’s a feature that can make a real difference to camp convenience, such as allowing you to swap ends in a tent without your zip now inconveniently facing away from the door if you find you’ve pitched on a slope, as well as easily sitting up without leaving the warmth of the bag.

The shape is a relaxed mummy with a gentle taper that allows a good range of limb movement without too much dead air space to reduce efficiency. The hood is well-insulated and well-shaped with internal adjusters to cinch it in.

The shoulder baffle cinches in with internal adjusters and seals the bag up just below my neck. The main zip is smooth and snags rarely despite the unusual position which favours neither left- nor right-handed users, and it clicks closed at the top with a magnetic closure.

The footbox is well-insulated and well-shaped. The internal pocket is large and can take camera batteries, a torch, snacks and more.

The centre zip and slightly relaxed cut lets me sit upright with free arms to cook whilst still wearing the hood.

It’s a great bag for camp and very comfortable to sleep in.

The Mammut Perform Down Bag is warm with instant feedback on bare skin, it lofts well and the outer shell has excellent water repellency.

Compare the Mammut Perform Down bag to other sleeping bags with our comparative tests here