Horizon VestThe new Horizon Vest is warm without being bulky. This vest is ultralight and insulated with 37. 5 fill, which has an extreme weight to warmth ratio. The Horizon combines a windproof, insulated shell with side panels that stretch for a comfortable fit and freedom of movement. 37. 5 technology removes moisture before it turns into sweat, helping you maintain an ideal core temperature so that you can perform your best. Climate control clothing with 37.