C.Scope, MXL4-DBG/MXT4-D, MXL4 Digital Precission Cable Locator with 512Hz, 640Hz, 8kHz, 33kHz and 131kHz Tracing Frequency, Depth Measurement, USB, Bluetooth™, Data Logger and GPS, MXT4 Data Logging Transmitter and Professional Carry Bag
Do not require periodic recalibration.
A fully Automatic Daily Self Test (ADST) tests and confirms that they are functioning at their optimum level each day.