Sea To Summit Spark -9C/15F Down Sleeping Bag - Long Features: 850+ FILL Power, RDS-certified, Goose Down with Ultra Dry Down treatment for improved water resistance in damp conditions 10-Denier Nylon shell and lining. 10-Denier Nylon waterproof-breathable hood and footbox. Mummy Fit: Fitted cut with generous footbox and technical hood, to maximise thermal efficiency and minimise bulk and weight. Spark 7C/45F & 1C/30F Primary zip - 1/2 length #5 with zip-plow and two sliders. Spark -9C/15F & -18C/0F Primary zip - 3/4 length #5 with zip-plow and two sliders. Vertical chest baffles, horizontal baffles lower half and base. SPARK 7C sewn through quilted construction throughout. SPARK -1C/30Fbox wall baffles top half of bag and sewn through quilted construction lower half. SPARK -9C & -18C box wall baffle construction throughout. Spark 7C, -1C & -9C Standard front draft collar. SPARK -18C Double draft collars Spark 7 & -1 can't be paired. Spark -9 & -18: Pairs with Women's Sea to Summit bags. QuiltLock System integrates with StS quilts Spark -9C/15F Down Sleeping Bag - Long