The Therm-a-Rest Saros Sleeping Bag Series is a line of top-rated, synthetic-insulated unisex mummy bags engineered specifically for backcountry backpacking and mountaineering in cold, unpredictable, or exceptionally damp environments.
The Saros Family Line
The Saros is manufactured in three distinct climate models to suit your specific seasonal needs:
Therm-a-Rest Saros 32°F / 0°C: The lightest option in the lineup, optimized for warm summer camping and mild three-season backpacking.
Therm-a-Rest Saros 20°F / -6°C: The most popular model, built as a versatile three-season core bag for unpredictable spring-to-fall weather.
Therm-a-Rest Saros 0°F / -18°C: A robust winter option designed for sub-freezing temperatures and frigid mountain environments.
Unique Performance Highlights
eraLoft™ Synthetic Fill: Insulated with Therm-a-Rest's proprietary hollow-fiber synthetic blend. Unlike natural down, these fibers are completely non-absorptive, allowing the bag to retain its loft, dry incredibly fast, and continue insulating even if soaked by heavy condensation or tent leaks.
W.A.R.M. Fit Profile: Standing for "With Additional Room for Multiple positions," this unisex shape features a more generous internal girth than a restrictive traditional mummy bag. It gives side-sleepers and active tossing-and-turning campers space to shift naturally without pulling the insulation taut and creating cold spots.
SynergyLink™ Connectors: Equipped with removable, flexible elastic straps on the underside that anchor the sleeping bag directly to your sleeping pad. This stops you from rolling off your insulated mat onto the cold floor in the middle of the night.
Zoned Insulation Construction: Maximizes thermal efficiency while shedding weight by concentrating the majority of the synthetic fill on the top and sides of the bag. The bottom relies primarily on the insulation value of your sleeping pad.
Toe-asis™ Foot Warmer: Includes an ergonomically designed, heavily baffled internal pocket within the footbox to rapidly warm up cold feet.
Sizing and Physical Specs
The Saros line is offered in standard unisex sizing to eliminate dead air space:
Small: Accommodates sleepers up to 5 feet 6 inches (168 cm).
Regular: Fits individuals up to 6 feet 0 inches (183 cm) and weighs approximately 3 lbs 3 oz (1.45 kg) in the 20°F variant.
Long: Tailored for individuals up to 6 feet 6 inches (198 cm).
Whether you’re tackling mild summer trails or braving frigid mountain environments, the Saros Sleeping Bag Series offers tailored solutions for every adventurer.
