Full Throttle Men's Blue Medium Hinged Rapid-Dry Flex-Back Life Jacket is made with soft, comfortable, neoprene construction to deliver increased stretchability. The Poly-Span polyester/spandex inner provides a soft surface against your skin for all-day comfort. Large arm holes were built in for enhanced freedom of movement for easy twists and turns. The Flex-Back is a ultra comfortable, flexible vest for maximum mobility on the water. U.S. Coast Guard Approved Type III Life Jacket / Personal Flotation Device (PFD).