Mechanical pressure gauges are used in vehicles and machines to mechanically measure the oil pressure or air pressure in a pressure system. In a pressure system, MOTOMETER pressure gauges mechanically determine the pressure by means of a measuring unit with a Bourdon spring. The mechanical pressure gauges all have a metal housing in order to provide the bestpossible protection and stability and thereby guarantee a long service life. The instruments are illuminated by a flood light type. In the case of the standard types, the dial is black with white numbers and the front ring is of a black triangular design. A distinction must be made between single pressure gauges and double pressure gauges.