You searched for "test function"
Trumeter
Trumeter LCD Digital Panel Multi-Function Meter for Voltage, 68mm x 33mm
Part: DPM952
Trumeter compact LCD voltage meter for electrical system monitoring and testing.
Trumeter
Trumeter LCD Digital Panel Multi-Function Meter for Voltage, 45mm x 22.5mm
Part: DPM951
Compact LCD voltage meter for direct panel mounting in electrical control systems.