Sea to Summit Spark SpIII: Ultralight warmth and packability redefined. This down sleeping bag delivers exceptional performance for weight-conscious adventurers, boasting premium 850+ fill power down, a lightweight 10D nylon shell, and a tapered mummy shape for efficient thermal regulation. Experience unparalleled warmth-to-weight ratio and minimal pack size, perfect for backpacking, thru-hiking, and alpine pursuits.