The Simon jacket is ideal in very windy and freezing weather conditions. The jacket has been designed using lightweight, body-hugging materials so as not to restrict your movements when you run. The sleeves and part of the chest are in nylon with quilted inserts, 80 grams. This jacket has been designed with great attention to detail: thumb hole at the bottom of the sleeves to stop cold air from coming in, two concealed-zip front pockets, diagonal-zip back pocket for keeping your supplements, acc