The Reactor is made from 80g/m² Thermolite®—the lightest weight Thermolite® fabric available. Thermolite® is a hollow core fibre that provides amazing warmth for its weight and remains extremely breathable. The Reactor adds up to 8°C of warmth to a sleeping bag or can be used alone as a warm weather bag. Our bestselling sleeping bag liner!\n\n- Adds warmth to a sleeping bag\n- Mummy shape with a box foot\n- Draw cord hood with mini cord lock\n- Packs into its own UltraSil® stuff sack\n- Lighter in weight, more packable than fleeceRead More