Sonde Locator, 512 Hertz Frequency, Rigid Drain Locator with 8/5" and 1/4-20" Connectors for Locating & Detecting Small Sewer & Pipelines, Up to 25' Depth Water Line, Flashing for TransmittingProduct Features 512HZ Strong Signal This sonde makes your pipeline detection quick and easy. Furthermore, it is capable of working with any 512hz receiver. During operation, the LED will stay steadily lit. If it starts flashing, it indicates a low battery level. 2 Replaceable Connectors These two adapters can attach the sonde locator to drum machine or sectional cables separately. So they provide versatility in locating underground pipe and line