NEW MARINE NAVIGATIONAL LIGHT. NSN DEFINITION IS A LIGHT SPECIFICALLY DESIGHNED TO BE MOUNTED ON A MARINE CRAFT TO INDICATE ITS POSITION IN MOTION OR AT REST, ITS SPEED AND OR ITS DIRECTION OF TRAVEL. NSN 6220-00-548-6220. MPN MS17999-220. FMS-KNOX CLASS FF. COPPER ALLOY BODY. COPPER ALLOY ILLUMINATION DEVICE. GLASS LENS. USES DOUBLE CONTACT BAYONET CANDELABRA. 25 FEET LONG WIRE CABLE. LENS COLOR GREEN. ( LOOKS BLUE TO ME). DOES NOT COME WITH BULB. PICTURES ARE PART OF THE DESCRIPTION. FREE SHIPPING. CHECK OUT MY OTHER MILITARY SURPLUS LISTINGS.