This is a Pico Technology TA467 insulation tester designed for electric vehicle high-voltage systems, It features insulation testing capabilities at 250V, 500V, and 1000V.
The device functions as a True RMS digital multimeter capable of measuring AC/DC voltage, current, resistance, and capacitance.
It has an IP67 waterproof rating and includes a wireless USB interface to transmit data to a PC.