Sea to Summit Thermolite Reactor Extreme


Increases sleeping bag performance by up to 25 F (14 C) with super-insulating 110g/m Thermolite® fabric. Thermolite® is a hollow core fiber that provides extraordinary warmth for its weight and remains extremely breathable. Spacious design allows for a comfortable night’s sleep, even when the mercury plummets. Perfect for extending the season of your sleeping bag.

– 110g/m2 Thermolite® construction throughout

– Adds up 25°F (14°C) to warmth to a sleeping bag

– Mummy shape with a box foot

– Draw cord hood with mini cord lock

– Packs into its own Ultra-Sil™ stuff sack < - Dimensions: 84 in / 210cm x 36 in / 90cm


Ever wish your sleeping bag was warmer? The Sea to Summit Thermolite Reactor Extreme allows you to turn any sleeping bag into a modular sleeping system. Just shimmy into the Reactor Extreme before climbing into your sleeping bag an instantly increase the warmth rating by up to 25 degrees! Use with any sleeping bag or during the summer use with a bivy. Perfect for lightweight hunts with 3 season sleeping bags.

Additional information

Weight 1 oz