The Sea To Summit Trek -18°C/0°F sleeping bag is designed for adventurers who face extreme conditions. Its semi-rectangular shape offers an ideal balance between space and thermal efficiency, reducing the air to be heated while maintaining sufficient comfort to move freely. The down fill ensures superior insulation while remaining lightweight and packable, making it easy to transport during long hikes. This model incorporates an Ultra Dry Down 650 treatment, which enhances the water resistance of the down, allowing the bag to maintain its insulating properties even in damp conditions. The recycled polyester lining underscores Sea To Summit's commitment to sustainability by using recycled materials that help reduce textile waste. The comfort and limit temperatures of this sleeping bag are -11°C and -18°C respectively, with an extreme temperature of -39°C, making it ideal for winter expeditions or high-altitude adventures. The Free Flow zip allows adjustable ventilation for easy internal temperature regulation. Specifications of the Sea To Summit Trek -18°C/0°F: Fill: downUltra Dry Down 650 water-resistant treatmentLining: recycled polyesterShape: semi-rectangularFree Flow zipComfort Temperature: -11°C / Limit Temperature: -18°C / Extreme Temperature: -39°C Sleeping bag Sea To Summit ---Trek -18°C/0°F Navy Bleu Ocean