This mount fits into the end of our 1” x 1.5” tube gearboxes and allows you to attach any of our 0.770” pattern components. The mount has a ½” center bore to allow tubing or shafting to extend into the inside of the gearbox for added support. When using hollow tubing, it allows wires to be routed through the interior of the gearbox and down the hollow tube for a clean look.