Sea to Summit Reactor Thermolite Liner The &ldquo Reactor&rdquo is made from the lightest weight Thermolite, that Du Pont has yet approved. Thermolite is a hollow core fiber that provides extraordinary warmth for its weight & remains extremely breathable. Adds up to 15 degrees of warmth to a sleeping bag or, used alone, is the ideal warm weather bag. * Lighter weight, more packable than fleece * Adds up to 15 degrees of warmth to a sleeping bag * Mummy shape with a box foot * Draw cord hood with mini cord lock * Color of liner is black * Weighs just 9 oz * Packs into its own 3&rdquo x 5&rdquo sil nylon stuff sack Description Weight Reactor Thermolite Liner 9.0 oz