Marmot's Trestles 15 Sleeping Bag is a 15 degree mummy bag that will insulate you during 3-season use with Marmot's own Spirafil 120 synthetic insulation. A great all-around bag, the Trestles 15 features a full side zip, a hood draw cord, and a snagless draft tub. Marmot includes a compression stuff sack with the Trestles 15 Sleeping Bag.