Bat shaving is a service that thins the walls of a bat to induce a "trampoline effect" when the bat strikes a ball. The end cap is removed on a composite or aluminum bat and it is then placed into a maching lathe. Coordinates are programmed in according to the desired thickness of the bat barrel walls. The bat spins in the chuck of the lathe and a horizontally stationary cutting tool cuts the length of the barrel by "shaving" the inside. Once shaving is completed some bat shavers use a polymer/rubberized coating to strengthen the walls so premature flaking of the freshly cut composite does not occur through constant flexing of the barrel. The end cap is then attached with a strong epoxy and left to dry. Depending on the composite of the bat and the wall thickness balls have been tested to travel up to 62ft more than normal.