Sea To Summit SPARK PRO -1°C/30°F DOWN Sleeping Bag

Designed for men who enjoy ultralight hiking and bivouacking in three-season conditions, the Sea To Summit Spark Pro -1C/30F Down sleeping bag combines remarkable lightness with high-performance insulation thanks to Ultra-Dry Down-treated goose down. With an ISO lower limit of -1°C and a comfort rating of 3°C, it effectively handles cool nights in spring, summer, and fall. Weighing just 619 g (Regular size), it’s the perfect companion for trips where every gram counts.

Insulation and Thermal Protection of the Sea To Summit Spark Pro -1°C/30°F Down

The goose down filling has a fill power of 950+, providing an excellent insulation-to-weight ratio. The PFAS- and PFC-free Ultra-Dry Down treatment gives the down clusters increased moisture resistance without the use of fluorinated chemicals, thereby maintaining insulation performance even in wet conditions. The construction—with vertical baffles on the chest and horizontal baffles on the lower section—ensures even distribution of the fill and prevents cold spots. The front wind collar and technical hood round out this thermal system for nights when temperatures drop toward the lower end of the temperature range.

Ergonomic Design and Ventilation for a Comfortable Night’s Sleep

The ergonomic mummy shape conforms to the body’s contours to minimize the volume of air that needs to be warmed, while the anatomically shaped footbox provides ample space for the feet to rest naturally without compressing the insulation. The Free-Flow zipper system, combining a YKK #5 side zipper with YKK #3 zippers for the footbox and shoulder, allows you to precisely adjust ventilation according to nighttime temperature fluctuations. This thermal versatility prevents overheating on milder nights without compromising protection against cold drafts.

Technical Materials and System Compatibility

The 10D nylon outer shell features a PFAS-free DWR treatment that repels light moisture, while the highly breathable 10D nylon inner lining promotes moisture wicking. The sleeping bag is RDS (Responsible Down Standard) certified, ensuring the ethical traceability of the down. The QuiltLock system allows it to be paired with Sea To Summit quilts to expand sleeping options depending on conditions. It is also compatible with the brand’s women’s sleeping bags for use as a two-person set. The 5.3 L packed volume and Regular size, suitable for people up to 185 cm tall, round out the set’s ultra-packable profile.

Accessories and Eco-Design

The Spark Pro -1C/30F Down comes with an Ultra-Sil compression sack and a storage pouch. The compression sack is made from 40D recycled nylon and is bluesign-approved, an independent standard certifying textile production with reduced environmental impact. These material choices are consistent with the PFAS-free treatment applied to the entire product.