For ultralight backpacking and alpinism it is difficult to conceive a bag so reliably warm being any lighter. Perfect for high mountain use during the summer and at lower altitudes in Spring and Autumn. Specifications Plasma(TM) 10D outer shell is incredibly light and exceptionally breathable 469g of 90-10 Russian Goose Down with a minimum fill power of 800 Alpine fit with EXLA(R) system improves loft and maximises thermal efficiency Slanted box-wall baffles throughout Ground level side seams 7 baffle low volume anatomically shaped hood 4 baffle anatomically shaped and offset foot-box Full length Gemini(TM) zip baffle Plasma(TM) 10D inner throughout Supplied with waterproof roll-top stuff-sack and storage cube Weight : 770g / 27.2oz 100% Polyamide outer/inner, Down fill Plasma(TM) 10D outer shell is incredibly light and exceptionally breathable Alpine fit with EXLA(R) system improves loft and maximises thermal efficiency Full length Gemini(TM) zip baffle A six-baffle foot piece, our most advanced design, and featuring both our Bulls Eye Technology and offset Sharks Toe foot constructions. Supplied with waterproof roll-top stuff-sack and storage cube