Finally the miracle jacket is here at only 123 grams the castelli idro jacket offers full gore tex waterproof protection the most breathable gore tex ever made and permanent water repellency and it all folds down to fill just half a pocket now you dont have to choose between a small jacket or a protective one to carry with you castelli gave it a close to body race fit and functional details like the ykk waterproof vislon zipper and a zipped opening to access your jersey pocket