Pool Cue: Cue Sticks used at WPA competitions should comply with the following during play at the table:
The cue tip may not be of a material that can scratch or damage the addressed ball. The cue tip on any stick must be composed of a piece of specially processed leather or other fibrous or pliable material that extends the natural line of the shaft end of the cue and contacts the cue ball when the shot is executed.
The ferrule of the cue stick, if of a metal material, may not be more than 1 inch (2.54 cm) in length.