1. Using high-quality materials, the quality is guaranteed 2. AC range: AC80.0-300.0V/300.0-450.0V (depending on the range you ) 3. Automatic power saving: Power saving when power is off. The power savings will continue to accumulate the time you turn it on 4. Small and beautiful appearance 5. High-definition LCD color display, the display is clearer and more intuitive.Wide range of applications parameter: Display color: red orange yellow white green blue Protruding size: 45x16mm Installation : rail type Measurement accuracy: 1% 2 words Measurement speed: 2 per second AC current: AC 0-99.99A, minimum resolution 0.01A Power frequency: 45.0hz -65.0hz Power factor: 0.00-1.00pf Active power: 0-45000w When the active power is between 0 and 9999.9w, the display accuracy is 0.1w Electric power: 0-999999kwh, when the electric power is between 0 and 999.99 kwh, the display accuracy is 0.01kwh, the display accuracy between 10000.0-9999.9kwh is 0.1kwh, and the display accuracy between 10000.0-999999kwh is 1kwh Application 1. According to the wiring , connect the green wire of the secondary current transformer to the blue end of the instrument, and make the wire of the measurement loop pass through the hole on the current transformer. 2. Power on and the measurement and display the results. 3. Press and hold the button for 5 seconds, the power is zero. Precautions: 1. The wrong connection will damage the meter 2. The meter can only be used to measure 50hz AC mains, for input (green terminal) and secondary current transformer (blue terminal) will be damaged. Measure square wave, inverter output and calibrated sine wave Colour:As Shown Material:plastic type:B Package Contents: 1 x Meter( AC40-300V ExternalCT) 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 a little different from the real thing. The measurement allowed error is +/- 1-3cm.