Designed primarily for comfort, the Silk Blend Liner adds warmth to your sleeping bag via the 72% Thermolite® Pro yarns with infra red technology, Thermolite® EcoMade fibres and 28% silk. The combination creates a soft, luxurious sleep environment.Two versions are available. The Rectangular with Pillow Sleeve has Comfort Stretch Panels along the seams to boost sleeping comfort. The Mummy version has practical shoulder openings which aid with temperature regulation.