Those who want to sleep well but carry lightly will find a reliable partner in the Spark -1C down sleeping bag from Sea to Summit. The ultra-thin outer material of the sleeping bag and the strategically placed down should not mislead you about how well this sleeping bag retains the body heat of the sleeper. Filled with RDS-certified goose down with 850+ fill power and treated to be PFC-free, the Spark -1C offers optimal thermal insulation from late spring to autumn. The technical hood and zipper cover keep the warm air inside the sleeping bag, while the silky-light inner fabric ensures comfort and maximum breathability. The outer material of the Spark -1C is made of lightweight 10D nylon, and a water-repellent hood and footbox with PFC-free DWR coating protect against wind and condensation. The sleeping bag can be compressed to save space and comes with a siliconized compression sack and a storage bag. Weighing only 493 g (regular size) and with a compressed volume of 4.5 liters, it is ideal for trips where every gram counts.