Level Guage opens or closes electrical circuit depending on liqud is rising or dropping in order to reach fixed level. It is convinient to guage due to float on the switch. Fixed level guages of level switches are from 100mm to 1000mm. Product has one contact NA (Normal Opened) opon. Electrical connecon can be made due to square socket on the product. It is manifactured as 1'' BSP mechanical connecon.