The T-handle garboard drain assembly is designed specifically for competition ski boats, with their unique hull and interior configurations. The flange is threaded from the back side so the plug can fit inside the boat. The 1/2" size has three mount holes, the 3/4" size has four mount holes --all with #8 fasteners (SOLD SEPARATELY). The T-handle is long and easily accessible, to avoid fumbling through dirty bilge water. It also incorporates a hex for a wrench operation. The plug is solid to prevent freeze damage.