Sea to Summit Spark Pro Ultralight Down Sleeping Bag – 30°F, Long

The Sea to Summit Spark Pro Ultralight Down Sleeping Bag is built for serious backcountry adventures without the bulk. This technical bag blends maximum warmth with the smallest possible pack size, making it a strong companion for two-season backpacking, bike packing, and touring. Available in Regular and Long, with two temperature options (30°F and 15°F), it adapts to a range of nights from cool to cold conditions. The contoured mummy shape, front draft collar, and strategically placed zippers help you settle in with less draft and more comfort, whether you’re climbing a pass or resting after a long day on the trail.

Warmth, loft, and moisture management

• 950+ fill power goose down certified to Responsible Down Standard, treated with Ultra-Dry Down to help loft when moisture is present
• Hybrid box baffles in the torso for consistent warmth, sewn-through baffles in the legs to reduce weight
• Front draft collar wraps the neck and is oversized at the shoulders to minimize drafts without restricting movement

Breathable comfort and rugged construction

• Featherweight 10D nylon shell with a PFC-free DWR finish provides water resistance while staying highly breathable
• Breathable 10D liner promotes air flow to reduce dampness and keep night comfort high
• YKK #5 side zipper with plow plus YKK #3 zipper at the footbox and shoulder for snag-free operation with minimal weight

Temperature-specific design and packability

• 30°F model uses a mix of box and sewn-through baffles for warmth with reduced weight; 15°F model uses full box baffles for maximum warmth
• Includes Ultra-Sil compression sack and a storage cube for organized packing and quick loft recovery
• Both Regular (up to 6'0") and Long (up to 6'6") sizes fit different body types for comfortable nights out

Sea to Summit backs the Spark Pro with a lifetime guarantee against defects in materials or workmanship. The Free Flow Zip system supports versatile venting and can open the bag flat as a quilt for warmer camp nights. Designed for backpackers, bikepackers, and tourers who value warmth, weight, and packability, the Spark Pro offers a nuanced balance rather than a one-size-fits-all solution. Individual experiences vary with climate and personal comfort, but many users find this bag expands their opportunities for outdoor trips by reducing bulk while preserving loft and warmth.