Sea to Summit Thermolite Reactor Compact Plus Mummy Liner is a sheet bag to take with you on multi-day treks, trips or nights in a refuge! Thanks to its double weight fabric it can increase the performance of the sleeping bag up to 11 °! In fact, it is made with a combination of two superimposed materials depending on the area of the bag, in correspondence with the areas of the body that need more heat: chest and feet. All in a really low weight: only 236 g! Sea to Summit Thermolite Reactor Compact Plus Mummy Liner sleeping bag liner