Features Convenient Connection: Just download the APP bluetooth connection on the mobile phone to detect, real-time detect the charging status, voltage, current, capacity and other indicators of the USB power supply, quickly identify, and be able to identify QC2.0 and QC3.0 modes. Resistance Detection: Use the voltage difference method to measure the resistance value of the data line. By detecting the voltage of different data lines, the pros and cons of the data lines can be judged (special load is required for measurement). The quality of the charger battery can be identified by capacity and energy detection. Screen: 1.44-inch high-definition LCD screen, 6 kinds of dazzling color measurement interface, multi-directional angle conversion, the screen supports four-way rotation, after the mobile phone is connected to the APP, the test data can be saved as an EXCEL table, which is convenient for users to view the complete data. Note: UM34 does not have a communication version and does not support any communication between PC and mobile phone anyway. The UM34C is a communication version connected via Bluetooth. The UM34C has no PC software, only a mobile application. Mobile phone 5.0 and above, support 18 languages, Chinese, English, Russian...)If you encounter problems during use, you can check the product's built-in Chinese and English help interface. Compatibility: Some mobile phones are not compatible with our bluetooth board, please purchase carefully, not suitable for NOTE8/S8, APP only supports 5.0 and above. Allows apps to run in the background without cleaning up. Allow the application to start automatically. Keep the app running when the screen is locked. Don't clean it up. type-c is only used for measurement, and does not support all type-c fast charging and does not trigger. Specification: Product Model:UM34/UM34C (Optional) Display screen:1.44 Inch color LCD display Voltage measurement range:4-24.000V                Voltage measurement resolution: 0.01V Current measurement range: 0-5.0000A              Current measurement resolution: 0.001A Capacity accumulation range: 0-99999mAh      Voltage measurement accuracy: ±（0.2%+1digit） Energy measurement range: 0-999.99Wh          Current measurement accuracy: ±（0.8%+3digits） Load impedance range: 0.8Ω-9999.9Ω        Time measurement range:0-99h59min59s Temperature range: -10℃~100℃/0℉~200℉          Temperature measurement error: ±3℃/±6℉ Screen brightness setting: 0-5 levels          Auto screen off time: 0-9mins Voltage graphing range: 0-24.00V    Current graphing range: 0-4.000A Refresh rate:2Hz          Size: 7*3cm/2.8*1.2in Weight: Approx.48g~53g/1.7oz~1.9oz Package list: 1 x UM Tester Meter 1 x box Package List