These Screw-Out Deck Plates are molded to the highest standards. An internal, molded-in collar on the bottom holds deck plate bags or other round containers. Lubricate with Vaseline or Teflon grease. Keep threads clean with hot, soapy water. Avoid contact with acetone or strong solvents. Constructed of UV resistant injection molded ABS. Installs with six #8 FH fasteners (not included). When installing, use silicone sealant on hull or deck surface.