The Cobalt Springs is a great choice for any family camping trip. The outer is a durable 190T Polyester that looks as good as it feels. The 100% cotton flannel lining provides an extra soft feel when you are sleeping under the stars in the wilderness or the backyard. The insulation is a hollow-fiber that gives you great loft and warmth at the same time. The zipper allows you to zip multiple Cobalt Springs bags together. A standard stuff sack is included. 4921677 Cobalt Springs +25deg 4900027 Rectangle Liner - PolyCotton 4900029 Rectangle Liner - Brushed Polyester