These pressure gauges are suitable for measuring of liquid and gaseous medias, although this should not be viscous or susceptible to crystallization. For aggressive media, which attack brass, other versions with stainless steel medium wetted parts are available. The two independently indicating Bourdon tube measuring systems work in a stardy housing. Both pointers turn around the same axle and indicate the values separately. The pointer on the low-pressure side has the form of a dial. On this dial the pressure difference between the low and high pressure side is given which may not exceed 50 % of the full measuring range. Each single value can be read off directly .