The dual-frequency HDD sonde/transmitter operates at 12 or 19 kHz. The FX12/19 sonde has a depth range of up to 19.8 meters. It is compatible with DigiTrak F2 and F5 locators. The probe transmits 12 clock positions and inclination with an accuracy of 0.1%. The sonde frequency is selected when the battery is turned on in the field. The activation principle is similar to that of dual-frequency models of sondes for the F5 locator. The frequency is selected when inserting batteries into the battery compartment: 12 kHz — when inserting batteries from the top; 19.2 kHz — when inserting batteries from the bottom. The selected frequency is set after 5 seconds of vigorous shaking. The sensor continues to operate for 40-50 seconds after the batteries are removed, so when changing the frequency, it is necessary to hold the sensor for one minute without batteries. 1 year warranty. Free shipping.