DECK PLATES FOR HOSE are chrome plated zinc with black plastic cap. Complete with key, O- ring and retaining cable on cap. Cap has slot between holes. Screw size is 8. Neck length measures 2-1/2". OD flange is 3-1/2". Hose size is 1-1/2". Gas deck plate meets requirements of USCG safety standards, January 31, 1977 for gasoline fuel systems, 33CFR183. Use spare O-ring 513008 and spare key 1248008ZNC.