1" D Nylon Black Transom Drain Plug by Seachoice®. Black nylon screw type drain plug features an "O" ring for positive sealing. Fine threads maintain sealing under high vibration conditions. Mounts in a 1" diameter hole and mounts with two #8 screws. Mounting flange: 1-1/2" x 2". Ideal for boat transoms, fish wells, ice chests.