The THERMOLITE® Reactor™ Extreme liner is Sea to Summit’s warmest knitted sleeping bag liner. If your adventures take you to colder climates, the Reactor Extreme will add plenty of warmth to a sleeping bag. Plus in warmer weather, it can be used as a ‘stand alone’ sleeping bag. The hollow core fibers of the THERMOLITE® fabric work like a polar bear's fur and, along with the knitted structure, trap plenty of insulating air. Super soft and amazingly stretchy, the Reactor Extreme uses a heavier version of THERMOLITE® to provide extra warmth for an incredibly comfortable night’s sleep. Use one to build your cooler-weather sleep system and to help keep your sleeping bag clean too.

BEST USE: Backpacking & Camping

WEIGHT: 14 oz | 399 g

LENGTH: 6 ft 10 in | 210 cm

PACKED SIZE: 6.5 x 4.5 in | 17 x 11.5 cm