This is a UNI-T UT673PV Solar MPPT Meter designed for testing photovoltaic panels.
It measures maximum power (Pmax) up to 800W, open-circuit voltage (Voc) up to 60V, and short-circuit current (Isc) up to 35A.
The device features a large LCD screen that displays all parameters simultaneously and offers both auto and manual testing modes.
It is self-powered by the solar panel being tested, eliminating the need for external batteries.