BKU (BKS) is designed to control one or two levels of filling or emptying of tanks, bunkers, etc. electrically conductive liquid and bulk materials (water, suspensions, ore, rock, coal, silage, flour, etc.) by changing the resistance between the electrodes of one or two level sensors. The unit is manufactured with output intrinsically safe electrical circuits of level "1a" in accordance with GOST 22782.5-78 and is marked "ExillC". The unit is installed outside explosion-proof areas of premises and outdoor installations. The unit is equipped with a sensor designed for installations in hazardous areas of premises and outdoor installations.