Welcome We are here to improve the looks of your homes garage like no other installer, dealer or door manufacturer. We manufacture and install Thunder Mounts with the garage doors and openers we sell. Thunder Mounts size chart is to determine the kit length for your installation. Measure from top of the support joist down to the bolt hole on the rail or flanges on your project. Now that you have that figured out, how about a new door or opener? Give us a call. 805-338-6680 Cell 805-262-2895 office
Thunder Mounts TMGTS-12 has a maximum length of twelve inches. This come is a set for one overhead door. Instructions, chrome ring and hardware included.