This is a Air cylinder rebuid kit for cylinders found on many tire machines. Ø75 12 22mm Seal Piston Pad: 2pc. Ø75 3mm Seal Piston Pad: 4pc. 20 30 7mm Seal Ring: 2pc. Ø25 2.5mm Seal Ring: 1pc. These are the air cylinders located underneath the table top that clamp the wheel when mounting tires.