The Cressi Circular 16mm (0.63") Bands are made from Super Powerful High Modulus Rubber with a Replaceable DYNEEMA Wishbone System. Cressi Power Bands are available in many different lengths to suit most any application. Any one of Cressi Band Guns can easily be converted to this convenient Band System. When the Wishbone is Frayed or Worn, just untie the old Wishbone and tie a new Wishbone in less than one minute. The Wishbone System can easily be tied while in the water. No more throwing a Band away due to worn, torn or frayed Wishbones.