Woodcraft Klucky Pucks Knee Sliders (BLACK) Klucky Pucks are the choice of Woodcraft staff members and hundreds of top racers. The pucks are made of a proprietary plastic that is extremely durable yet still provides the feel racers are looking for. The pucks are set on a thick leather backing and utilize super-strong double loop hook-and-loop that ensures that they will never get pulled off while riding. Made of extremely durable proprietary plastic. Set on a thick leather backing.