Features: The frequency meter offer wide voltage compatibility (100V/220V) and precise 45-65Hz frequency measurement, ensuring reliable power monitoring across diverse electrical systems. Featuring 72x72x61mm plastic housing with shock resistant design, this lightweight meter combines space saving installation and long terms durability for demanding environment. Ideal for industrial electricians, facility managers, and homeowners seek accurate voltage/frequency tracking in appliance diagnostics. Perfectly suited for factory machinery calibration, commercial generator room, and residential workshops requiring realtime electrical parameter verification. This double function frequency meter and voltage monitor safeguards equipment performances by detecting power fluctuations in HVAC systems, production lines, and backups power setups. Specifications: Voltage: 100V/220V Frequency: 45-65HZ Exterior dimension: 72x72x61mm Opening size: 67x67mm Component: Plastic Suitable for building power systems, community power monitoring, distribution box Package Includes: 1pcs Frequency Meter note: 1.Please allow 1-2cm errors due to manual measurement, make sure that you donot mind befores you order. 2.Due to the differences between different monitors, the picture may not reflect the actual color. Thanks for your understandings.