The B&B centerbaord pin cap was designed to improve the old plywood cap for the Core Sound models which was sealed with caulk and often was damaged when removed.
The new pin cap is machined from UHMW plastic with an integral O-ring that seals on a smooth epoxy coated or painted surface. A blind hole in the back side accepts the head of a 3/8" bolt so that the bolt head can be left on when making a centerbaord pin from a stainless steel bolt. This allows for easy removal of the pin with a pliers.
The cap is attached with 3 screws. We recommend sealing the screw holes with epoxy prior to installation or resin bushing the screw holes. The cap in intended to be installed with NO sealent as the o-ring makes a perfect seal over the pin.