Quarter-Turn Smooth Deck Plate with Internal Collar - Black - 5" The Sea-Dog; Quarter-Turn Deck Plate is constructed of UV stabilized ABS. Features a new locking system that prevents over tightening, jamming, and cross threading. These deck plates also feature an internal, molded-in collar on the bottom to hold deck plate bags or other round containers. When installing, use silicone sealant on hull or deck surface. Keep threads clean with hot, soapy water. Lubricate with Vaseline or Teflon grease. Installs with six #8 FH fasteners (not included). Avoid contact with acetone or strong solvents.