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!

• Adds warmth to a sleeping bag
• Mummy shape with a box foot
• Draw cord hood with mini cord lock
• Packs into its own UltraSil® stuff sack
• Lighter in weight, more packable than fleece
• Machine washable