This is a Air cylinder rebuid kit for cylinders found on many tire machines. 
These are the air cylinders located underneath the table top that clamp the wheel when mounting tires. Many times these cylinders bypass internally and cause the table to not grip the wheel or not function at all.
20*30*7mm Seal Ring: 2pc.
Ø75*12*22mm Seal Piston Pad: 2pc,
Ø75*3mm Seal Piston Pad: 4pc,
Ø25*2.5mm Seal Ring: 1pc