Review on Ultrasonic Water Tank Liquid Depth Level Meter Sensor: High/Low Alarm, Temperature Display, 3.3 Inch LED by Kevin Johnson

I understand why a lot of people have problems with this product. The instructions are poorly written. For it to work, insert batteries into both units and then press and hold the 'Set' and 'Alarm' buttons on the display unit without setting the tank depth. Phew, it's working properly now. I set the tank depth according to the instructions when installing the batteries, but the value was completely wrong. My display has no problem in the trailer about 100 feet from the tank.