Beckson Marine 6" Smooth Center Screw-Out Deck Plate - Black. This Boating & Marine Equipmentdesigned by the experts at Beckson Marine is made with a single start non-jamming extra strong self-cleaning buttress thread. This Beckson Marine 6" Smooth Center Screw-Out Deck Plate incorporates a self-aligning center and an innovative gasket to assure a watertight seal. A back-up sealing wall leaves the plate watertight even if the gasket is removed. Keep your boat accessing equipment running smoothly by installing a Beckson Marine 6" Smooth Center Screw-Out Deck Plate. Package Contents: Beckson Marine 6" Smooth Center Screw-Out Deck Plate Beckson Marine DP60-B: 6" Smooth Center Screw-Out Deck Plate - Black