A Meyer 3/4" Sheer Pin (part # 13004 or 13004C). This pin goes through the sector and A-frame to hold the plow in an angling position. This is for plows without angle or can be used in an emergency if the angling has problems. This goes through and turns a 1/4 turn to lock. This 3/4" one is for the 4 spring commercial blades. Only the smaller blades use a 5/8" pin.