The Helium GT series offers a more generous fit compared to the standard Helium range, making it ideal for extended use and those who prefer extra room to move. The Helium GT 400 features 449g of minimum 700 fill power DOWN CODEX-approved duck down and a high-performance, 100% recycled Helium 20D outer fabric. This combination ensures a well-sized, supremely comfortable, and lightweight bag that's perfect for backpacking and cycle touring, while still providing warmth for cooler nights.The bag employs a slant-baffle construction throughout the body to maximize warmth, enhance packability, and prevent down migration, ensuring consistent warmth and eliminating cold spots. The foot of the bag is designed with a four-baffle system to concentrate warmth around your feet, while the hood features a five-baffle system to optimize comfort and keep the down in place.Inside, the 100% recycled Supersoft 20D lining fabric with PFC-free DWR offers both breathability and durability for comfortable nights and a long lifespan. A full-length Gemini entry zip baffle minimizes heat loss and is reinforced to prevent snagging, while the low-profile magnetic Lode Lock closure and easy-to-use collar drawcords are effective even in low-light conditions.The Helium GT 400 is designed with a more generous GT Fit, maintaining the tapered shape of the Alpine fit but with a wider profile that does not compromise performance. With a Good Night’s Sleep Temperature rating of -5°C this bag provides dependable warmth for extended backpacking and travel during spring and summer. Helium GT 400 Sleeping Bag - Regular