Hole on the fiberglass dm 50 mms.
Maximum distance between the walls mms. 230, minimum distance 80 mms by cutting the fittings to size on a wall, the first part of the fitting is fixed with the relative nut. The second part is screwed onto the fitting already mounted on the wall of the boat.
Of course, the fittings are cut to size according to your needs. We recommend mounting and fixing the threaded fitting on the internal wall, so in the cockpit.
It is designed to receive the expansion plug dm 42 art. 6018. From the outside of the boat, the other fitting is screwed, which is designed to receive the non-return valve art. 6431.

Supplied with Cer-Deck washers. Closed cell foam material. They are used to align the seal on the walls of the boat.