SKU: SS24339 Weighs: 348g (Compact) Liner Type: Mummy Shape Liner Fabric: Poly Blend Liner Treatments: Odour Control Sea to Summit Reactor Extreme is a warm sleeping bag liner. It insulates well, packs small, and is breathable. The warmth-to-weight ratio is excellent. Sea to Summit says:  The THERMOLITE®Pro Reactor Extreme lin… Reactor Extreme Sleeping Bag Liner - Mummy w/ Drawcord