- Simultaneous display: This digital meter shows AC voltage, current and frequency at the same time for quick, effective monitoring of your electrical system. - No external power required: Operates independently with a built-in 120A precision transformer, eliminating the need for an external power supply. - Precision measurement: The 120A transformer provides accurate readings for reliable performance across a range of applications. - Compatibility: Designed for AC 50-60Hz power supplies; not suitable for square or modified sine wave circuits to prevent potential damage. - Use scenario: In a home electrical panel, monitor voltage, current draw and line frequency during appliance use or charging to ensure safe operation. - Use scenario: In a small workshop, verify load levels and supply stability to keep circuits within safe limits. - Use scenario: During equipment maintenance, check AC supply integrity before testing or replacing components.