The MXL4 Precision Locator represents a significant advance in cable detecting and tracing capabilities. Two versions of the MXL4 are available; the MXL4-D which has full data logging capability, and the MXL4-DBG which has full data logging capability, Bluetoothâ„¢ connectivity and GPS.. Innovative new features have been introduced enabling the MXL4 Locator and MXT4 Transmitter to provide high-end precision performance and a far more flexible approach to pipe and cable location.