Jack wolfskins texapore infinity flygrid fabric is very lightweight very waterproof and extremely breathable so itrsquos great when you start to sweat pounding up those steep trails and for an extra blast of fresh air you can open the pit zips if the weather improves and you no longer need it the mountain pass jacket packs down small for neat storage in your pack and thanks to the super light fabric the whole thing weighs little more than 300 grams