Horst Dynamic BL232 Black Water Tank Probe, (Pack of 4)
These Miracle Probes prevent false monitor readings of levels in grey and black waste water tanks. They eliminate false conductance between the metal probe point and the tank wall covered with sludge. Probes for black tanks feature a protective hood over the sensor to prevent malfunctioning due to toilet paper. They fit in the same 3/8" diameter holes that your present probes use. Black 4 pack