PISTON (STD - DIAMETER: 107.95 mm - WITH ALFIN): LISTER / HR-4 / HRA-4 / HRW-4 / HR-6 / HRA-6 / HRW-6 / REFERENCE NUMBER: 572-50122 / PISTONS INCLUDES PISTON PIN AND SAFETY RINGS / (The reference numbers given on the products are for checking the products.)