Veethree 37257 Tachometer 52mm Electronic 0 &ndash; 4000 (C/B) This is a 52mm gauge, chrome bezel/black dial, 0-4000 rpm range, alternator/ignition coil driven ,red pointer, spade type end connections. This gauge is suitable only for petrol engines. For diesel engines please check our "diesel tachometer". Can be programmed for 4, 6 or 8 cylinders and is perimeter lit.