Each participant shall provide him or herself with the ring costume prescribed or approved by the commission, and for males such costume shall include a foul-proof guard of the boxer's own selection, type to be approved by the commission, adequate as determined by the commission in its discretion to satisfactorily reduce the risks of the boxer being disabled by a low blow or blows received during the contest. Each participant shall provide him or herself with two mouthpieces of a type approved by the commission, and shall wear one of such mouthpieces while participating in a contest or exhibition. No shoes with spikes, cleats, hard soles or hard heels shall be worn in the ring.