Experience superior comfort and ultra-portability with the Spark Down Sleeping Bag by Sea to Summit. Boasting an impressive 850+ FILL Power and optimal warmth-to-weight ratio, this bag is a must-have for any lightweight adventure. Features RDS-certified, 850+ fillpower goose down with a non-PFC Ultra-Dry Down treatment for maximum thermal performance Ultralight, breathable 10D nylon liner and a 10D shell with PFC-free DWR keeps the hood and footbox highly water resistant Technical hood, anatomical footbox and an ergonomic mummy shape - ultralight doesn't have to mean ultratight YKK #5 zippers with zipper plow provide reliable, snag-free operation Baffle construction specific for each use: Sewn through for lighter weight (7°C|45°F), Hybrid box baffles in torso/sewn through in leg area (-1°C|30°F) or full box baffles for maximum warmth (-9°C|15°F) Sea to Summit Guarantee is offered for the Lifetime of this product Specifications Insulation: 850+ FILL Power, RDS-certified, Goose Down with Ultra Dry Down treatment for improved water resistance in damp conditions. Fabric: 10-Denier Nylon shell and lining. 10-Denier Nylon waterproofbreathable hood and footbox. Mummy Fit: Fitted cut with generous footbox and technical hood, to maximise thermal efficiency and minimise bulk and weight. Hood: Technical fitted hood with soft touch adjustment. Extra deep for cosy like feel. Comes With: Ultra-Sil™ Compression Bag & Storage Cell The temperature rating on Women's specific sleeping bags is based on a Comfort Rating. All other sleeping bags are based on a Lower Limit.  Max User Height Weight Fill Weight Compressed Volume Spark 7°C Regular 185cm 363g 150g 2.4L Spark 7°C Long 198cm 387g 172g 2.9L Spark -1°C Regular 185cm 493g 265g 4.5L Spark -1°C Long 198cm 536g 305g 5.1L Spark -9°C Regular 185cm 730g 480g 6.8L Spark -9°C Long 198cm 786g 540g 7.6L Spark -18°C Regular 185cm 1113g 840g 9.9L Spark -18°C Long 198cm 1204g 945g 10.6L