Waterproof probe, which can be used to detect PVC pipes and water pipes. It can accurately locate hidden blockages, pipeline blockages, and emit a buzzing sound to remind you. Sensitivity adjustable, integrated design for easy storage, anti slip handle for easy handling and carrying, and long service life. How to use: Adjust the receiver sensitivity switch to maximum. When you sense a signal source around the signal point during the detection process. Slowly reduce the sensitivity switch of the receiver to further narrow down the range of signal point search. Until it narrows down to a very small range point, it is the location of the blockage point. (Note: The smaller the sensing range point, the more accurate the blockage point will be.) Careful and patient operation during this detection process can find the precise blockage point.