The Sea to Summit Spark Pro 900+ Down Sleeping Bag -1°C | 30°F – RDS – Regular is an ultralight 3-season sleeping bag engineered for serious backpackers who demand warmth without unnecessary weight. Filled with premium 900+ fillpower RDS-certified goose down treated with non-PFAS Ultra-Dry Down, it delivers exceptional loft and thermal efficiency. Wrapped in featherweight 10D fabrics, the Spark Pro remains highly breathable while maintaining durability for backcountry use. The Free-Flow Zip system allows precise ventilation control or full quilt-style opening when conditions warm up.

Sea to Summit Spark Pro 900+ Down Sleeping Bag -1°C – Regular Key Features:

• Premium insulation: 900+ fillpower RDS-certified goose down with non-PFAS Ultra-Dry Down treatment.
• Ultralight 3-season performance: ISO lower limit rating of -1°C.
• Featherweight construction: 10D nylon shell and breathable 10D liner for comfort and minimal pack weight.
• Free-Flow Zip system: Full-length YKK #5 side zip plus shoulder and footbox zips for ventilation and quilt conversion.
• Box wall baffle design: Prevents cold spots and maximises loft retention.
• Ergonomic mummy shape: More generous cut for improved sleep comfort without excess bulk.
• Technical hood and draft collar: Designed to retain warmth on cooler nights.
• Lifetime Guarantee: Backed by the Sea to Summit lifetime product guarantee.

Specifications – -1°C Regular

• Best Use: Ultralight Backpacking
• Performance: 3 Season
• ISO Lower Limit: -1°C
• Women's ISO Comfort: 3°C
• Weight: 619g
• Fill Weight: 310g
• Compressed Volume: 5.3L
• Compression Sack: 8L included
• Fits Up To Height: 185 cm

Designed for ultralight missions where warmth, ventilation flexibility and pack efficiency are critical.