Underside of flange has a groove cut in it to trap a bead of silicone between it and the mounting surface. Flange head is very evenly polished. Nut mates with threads exactly; hardness of metal is excellent.
Suitable for marine boat,yacht,kayak etc, a good damage part replacement choice;
Two slightly protruding pins within the interior of the drain allow for a wide blade flat screwdriver to be inserted and prevents the flange portio from turning when nut is installed.
About us: We have our own factory that we could give you nice service and highq quality