Right hand leveling box assembly CAT I Heavy Duty Leveling box has 5/8 inch clevis pin hole. Bottom fork has a 5/8 inch hole. For 5/8 inches thick arm. For various Massey tractor models such as MF35, 50, 135, 150, 230, 235, 245, Industrial 20, 2135, 202, 205, 302, 304