Constructed of fiberglass filled injection molded nylon. Contains no metal and does not require grounding. Has a special cap with a built-in key for easy cap removal. The hinged key can be locked in the upright position to open or close the fill and then recessed into the cap for a flush surface. 1-1/4\" 11-1/2 NPSM straight cap threads. Installs with three #10 FH fasteners (not included). Will not work with pressurized oil injection systems. Chrome plated brass safety chain.