Bright & Luminous Color for Better Visibility. Polyester Outer Shell with Enclosed Foam for Greater Buoyancy in Water, Lightweight, excellent wear flex fatigue resistance, low water absorption. Each vest has been matched with a whistle, useful when emergency occurs, Reflectors at shoulder and back is convenient for rescue worker searching for. Buoyancy: >100N, A Necessity for Water Sports, Boating, Water Skiing, Water Rides, Surfing, Jet Skiing, Participating in Rescue, Swimming Pool .