Mountain Equipment Helium 600 Sleeping Bag Alpine fit with tapered lower leg for improved thermal efficiency and weight reduction Trapezium 4: 4 baffle trapezoid foot piece with Bull-Eye technology for down control and low weight DC5 Hood 5 baffles and anatomical fit provide high levels of warmth and down control with low weight Solus Collar For optimum lightweight insulation with down draft tubes Slanted Box Wall Construction Offers a stable and superlight structure with excellent stability and down control