Primed split mount. The pre-flashed, pre-assembled mounts are manufactured of fiber cement with an ABS flange. Providing a water management solution, blocks are easy-to-install and provide a clean finished look. To be used on spigots, gas lines, bib lines, and door bells. 6" x 8-1/2". Surface Dimensions: 6" x 8-1/2", Round Knockout: 1" diameter, Material: Fiber Cement, Color: Primed