The tube rail chain extension kit is to be used in conjunction with the 5 piece rail system for the Chain Drive 550, when the door measures 8 ft in height. The extension kit rail replaces the end section of the 5 piece tube rail system. Installation is easy with no additional assembly hardware. Extension kit cannot be used on the Chain Drive 500.
Easy to install
Easy to install
Extend the 5-piece chain drive tube style rail for a 7 ft high door to an 8 ft high door