This Rugged Molded Shell is built to last!  Made from high density, high molecular weight polyethylene. The Premolded Solid Foam Core is made from top grade expanded polystyrene (EPS) foam that conforms and thermally fuses to the shell. The high tensile strength shell is resistant to impacts and is impermeable to water. The ultraviolet radiation resistant shell protects the foam core from wave action, animals, marine organisms and gasoline.  In addition to fast, secure, easy mounting, these floats have survived major hurricanes remaining attached to docks that were decimated by the storms.  They are very durable made to last longer than any other flotation foam available. Also available in many different thicknesses and sizes.