Designed for some of the most demanding and technical ascents in the world, the Mammut Altitude EXP 5 Season 22 Degree Down Sleeping Bag ensures that you are well rested for another full day in the alpine. Where the Altitude EXP stands apart is with its ShelterTX waterproof, breathable two layer shell, which protects the down insulation from moisture. This construction makes the bag well equipped to handle challenging conditions without having to be coddled like more traditional down sleeping bags. In addition to its two layer construction, the EXP 5 Season bag is also unique from other bags in the line since it has a removable fleece lining in the foot box. This feature improves insulation and enhances overall comfort. Mammut's Trinity construction provides exceptional insulation in the head and feet, both of which tend to run cold in extreme temperatures. The box mummy construction allows for more loft, while giving an all around better fit. An advanced baffling chamber design prevents the down from slipping, and as a result eliminates cold spots when laying on your side or sitting in an upright position. A large neck collar eliminates draft while you sleep, and a zippered inside pocket stows any essential item you might need throughout the night, without having to expose yourself to the cold.