The North Face Summit Series Men's L4 Jacket is a synthetic insulation midlayer for your rise to the summit in cold, wet conditions. The alpine can be tough, so let ThermoBall™ insulation provide the warmth for you along the way. It traps heat, while remaining lightweight and packable for the times you don't have it on and have to carry it in your pack instead. When on stretch side panels allow for natural movement and the hood is ready to warm your head. When weather conditions are dicey, this is a layer you can count on.