BECKSON MARINE DP40-W-C Beckson 4" Clear Center Screw-Out Deck Plate White Access without tools. Self-aligning center & gasket assures watertight seal. Patented back-up sealing wall leaves plate watertight. Use in compartments where change in air pressure due to temp or oil canning can occur. The Beckson Screw-Out Plate was designed to provide access without the use of tools, Deck plates are used for access to shut-off valves or back-fastenings, inspection, and clean out for tanks and compartments. MODEL NO - DP40-W-C