A very poor conduct of heat, silk will trap a lot of warmth within your sleeping bag making it a very warm compact unit. A silk liner is also a must when traveling in hotter climates, its natural heat managing characteristics keep the body comfortable in both extremes of hot and cold. Ounce for ounce our most heat efficient liner. Constructed from 100% natural silk. Weight: 6 oz Pack Size: 4 x 2 Color: Black