The worlds softest urethane golf ball the 3 piece 55 compression duo urethane is designed for the feel player who demands tour performance spin and the softest feel inner mantle layer the du pont hpf inner mantle layer provides velocity for maximum distance cast urethane the soft thin cast urethane outer cover is the most premium material available and provides exceptional spin and control on approach shots wilson staff is just one of three golf ball manufacturers that uses cast urethane in g