The "Reactor" is made from Thermolite®, a hollow core fiber that provides extraordinary warmth for its weight and remains extremely breathable. Adds up to 15 degrees F / 8 degrees C 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 F / 8 degrees C 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 8.7oz
• Packs into its own 3" x 5" sil nylon stuff sack