The ultimate sleeping bag for cold weather carping. The upper layer boasts Foxs new synthetic silicone treated down, which is lighter and warms up to body temperature much faster than standard hollow fill creating our warmest ever sleeping bag. The base layer benefits from 7 Core Hollow Fibre filling, which is silicone treated to help maintain shape and expand fibres. Offset panel stitching allows warm air to be retained inside bag for longer. Ripstop soft Polyester outer base layer fabric which aids breathability on a bedchair mattress. Waterproof 20,000mm hydrostatic head Ven-Tec Ripstop upper outer layer.