Sea to Summit Reactor Sleeping Bag Liner

The Reactor is designed to add a significant thermal boost, typically increasing your sleeping bag's temperature rating by several degrees. While exact performance varies based on your sleeping bag's insulation and your personal metabolism, it is highly effective at trapping body heat in cold-weather conditions.

Yes, the mummy-shaped design is versatile enough to fit inside almost any standard mummy-style sleeping bag. Because it is lightweight and flexible, it won't feel bulky or restrictive once you are inside.

The liner is designed for a snug fit to maximize heat retention, which means it feels more like a fitted layer than a loose sheet. While it is easy to enter, the mummy shape is streamlined, so it is best suited for those who don't mind a closer fit while they sleep.

Using a liner acts as a protective barrier between your body and the sleeping bag's interior, catching sweat, oils, and dirt. This significantly reduces the frequency with which you need to wash your sleeping bag, which helps preserve the loft and longevity of your down or synthetic insulation.

Absolutely. On hot nights or during summer travel, the liner can be used as a standalone sleep system. It provides a comfortable, hygienic layer that is much easier to wash than a full sleeping bag.