Product Description Extend your garage door opener with ease! The EKCC Garage Door Opener Extension Kit from Genie helps extend your three-piece chain-drive c-channel rails to fit an 8-foot-tall door. Our extension kit is compatible with Genie model 3022, ChainMax 1000 garage door opener, and is easy to add to the existing rail and chain that comes standard with the Genie garage door opener. This 8 ft extension kit includes the rail extension, chain section, master link, and hardware, making it easy to install yourself. From the Manufacturer The extension kit for C-channel chain drive garage door opener rails is to be used in addition to a 7' (3-piece) chain rail to accommodate an 8' high door. For use on Genie Revolution Series chain drive garage door openers.