Reactor Sleeping Bag Liner

About the Sea to Summit Reactor

The Thermolite Reactor is Sea to Summit's most popular sleeping bag liner. The minimalist design delivers a lightweight and practical way to add warmth to an existing sleeping bag across a range of pursuits; from backpacking to alpine trekking, family camping and more.

The cosy Thermolite fabric provides an excellent warmth-to-weight ratio, increasing the performance of your sleeping bag by up to 8°c while remaining breathable to wick heat moisture away from the body keeping you dry.

The Thermolite Reactor can be used on its own or as a sleeping bag liner to boost insulation in colder weather. Liners also help in keeping your sleeping bag cleaner and fresher for longer by reducing the build-up of dirt and oils. Great for a range of travelling experiences, from alpine and backcountry tours to tropical camping, backpacking and anywhere else you choose to lay your head.

The tapered shape takes up little pack space and offers peace of mind that should the nights turn cool or the accommodation falls short of expectations you can curl up in comfort for a good night's sleep. At 248g it's small enough to fit in a pocket! A drawcord hood helps seal out the cold while contrasting colour along the top edge lets you find the entrance quickly in low light. A boxed foot end lets your feet rest in a more natural position.

The Thermolite® Reactor from Sea to Summit is a travel essential with assured quality and 3-season versatility.