Genie 22438A04.S Shoulder Bolt 5/16" X 11/16" for Rail Clamp Garage Door Openers
BOLT, SHOULDER, 5/16" X 11/16".
This bolt fits through a pre-drilled hole in the rail clamp, the rail itself, and an additional clamp. It is then secured with a 24121C05.S Serrated Hex Nut.