Sea to Summit Spark Sleeping Bag

The '15' in the name refers to its comfort rating of approximately 15°F (-9°C). It is designed as a 3-season bag, making it ideal for chilly spring, autumn, and high-altitude summer nights where temperatures hover near freezing.

The hydrophobic treatment helps the down resist moisture absorption and maintain its loft if you encounter condensation or light dampness inside your tent. However, it is not waterproof, so you should still use a waterproof stuff sack or pack liner to keep the bag dry during heavy rain or river crossings.

The Spark 15 uses a performance mummy cut, which is designed to be snug to maximize thermal efficiency. If you are a restless sleeper who prefers a lot of room to sprawl, you might find this fit tighter than a traditional rectangular bag.

Yes, the full-length zipper allows you to couple this bag with other compatible Sea to Summit sleeping bags. This is a great feature if you are camping with a partner and want to share warmth.

Thanks to the high-quality 850-fill goose down, this bag is exceptionally compressible. It packs down to a very small size, making it an excellent choice for minimalist packs where space is at a premium.