... gold plated case,brass polished case, all this can take with front flange, backflange and U-clamp.BEZEL MATERIAL:Steel black ... , steelroll ring (or bayonet threaded ring), type: snap on, roll ringTUBE&SOCKET: steel with nickel plated, phosphor bronze ,SS and so on ... , steelroll ring (or bayonet threaded ring), type: snap on, roll ringTUBE&SOCKET: steel with nickel plated, phosphor bronze ,SS and so on ...