Measurement accuracy: 1% ± 2 characters. Frequency: 45.00-6500HZ. Power factor: 1.000-0000 Measurement speed: about 2 times per second Installation method: track type (common guide rail in the market) Display: Voltage display 4-digit red 0.31-inch LED digital tube, Current and frequency display use 5-digit red 0.31-inch LED digital tube, active power, electric energy (electricity) display use 5-digit, green 0.31-inch LED digital tube. Measuring range: AC voltage: AC80.0-300.0V, (or AC200.0-450.0V, users should propose according to their needs when ordering) AC current: AC0-100.0A, when the measured current is less than 100A, the current display resolution is 0.01A, when the measured current is greater than 100A, the current display resolution is 0.1A, and the range is automatically converted. Active power: (measurement voltage AC80.0-300.0V) 0.0-30000W (AC200.0-450.0V: 45000W) Electric energy: 0.000-99999kwh, decimal point automatic conversion. The external transformer (hole diameter 155mm) can meet the national standard 21-25 square (mm) standard copper wire passing through. Extreme working conditions: Working temperature: -10 - +60℃ Working humidity: 10-80% (no condensation) Working air pressure: 80-106kPa Sunlight exposure: no direct exposure Specifications:A:Hole Diameter 15.5mm (External Transformer) Colour:White Material:ABS Package Contents: 1 * power tester Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.