Going Ultralight doesnt have to mean suffering because we never skimp on our lightweight bags Wed rather find a way to shave the weight and innovate on performance like using Flex technology for our Nitro 30 We build in Flex between the shoulders and knees so you get the comfort and thermal benefits while saving precious ounces Our smart Foot Box Venting lets you customize the climate in the lower half of your Nitro without adding the weight of a fulllength zipper Ultralight speed with fullfeatured comfort