6plastic, polyethylene, molded, ty i, cl l, spec l-p-390; 1.280 in. O/a long; 1.280 in. O/a wide; 0.690 in. Dia; plug is l shaped with threads located at each end, 0.5625-12unc-1ar special, 0.5060 spl pitch dia; color green; item used on mine, apers m18a1