1. Mobile phone APP interface function introduction Use the mobile phone Bluetooth function to wirelessly connect the product with the attached mobile phone APP software to achieve more measurement and control details, so that the measurement technology has no boundaries 2. Brand new materials and new upgrades 3. When the USB tester is on, click the bluetooth during the measurement, the power is turned on, the bluetooth indicator light flashes from the upper left corner to the upper right corner of the application, open the pop-up menu to select the current online model. The UD18E test application software , and the USB tester model, UD18, the Bluetooth above allows Bluetooth to be turned on and returns to the main application interface. 4. The left corner turns blue, indicating that the measurement is in the online communication state, User manual, PC software installation manual, PC software and Android APP download link: http://.mediafire.com/folder/h6n70klgx5gua/UD18L 5. IOS APP: search for E_test in the to download App Android: https://.mediafire.com/file/0jiio43c0vuu1wx/U_Meter-Phone_mobile.apk/file Android app: search for e-test on to download Product Description Model: Voltmeter Type: Portable Energy Meter Color: Black Material: plastic Package Contents: 1 x Voltage and current 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.