The Mountain Equipment HELIUM 400 LONG is your perfect companion for light trekking tours and bike packing adventures, especially for those who need a little more length. With only 403 g of high-quality, CODEX-certified duck down and 100% recycled, robust Helium 20D outer material, it scores with an extremely small pack size and impressive thermal performance. The slanted box chamber construction keeps the down reliably in place, prevents cold spots, and provides cozy warmth down to about 43°F. The anatomically shaped, five-chamber hood and four-chamber foot section offer additional comfort, while the flat Gemini™ zipper and Lode Lock™ system ensure effortless handling—even at night. The soft, breathable inner material guarantees a comfortable sleeping climate from spring to fall. With the HELIUM 400 LONG, you'll sleep relaxed, warm, and well protected on your tours – no matter where your adventure takes you.