The REI Kilo Flash 40 sleeping bag is a lightweight, ultralight mummy-style sleeping bag with a +40°F temperature rating, designed for warm weather camping. It features a down and synthetic hybrid insulation, is very packable, and known for providing good warmth for its low weight.

Key features

Temperature rating: +40°F, designed for mild summer conditions.

Insulation: A hybrid of 750-fill down and synthetic materials.

Design: An ultralight mummy bag intended to be snug and minimize weight.

Packability: Compresses to a very small size, making it easy to pack.

Excellent warmth-to-weight ratio for its price.

Very packable and lightweight.

Comfortable for its intended use.