UT658 USB Current Voltage Detector with LCD Display and High/Low Voltage Alarm Easy Voltage and Current Monitoring: Simply plug the USB male connector into a 5V charger and the female connector into your mobile phone or other devices to instantly read voltage and current parameters. This straightforward setup allows for quick and efficient monitoring of your device's charging status. Comprehensive Data Storage: The UT658 features the ability to detect and store up to 10 sets of input capacity (mAH) data. To utilize this feature, connect the unit to your mobile power source, power it on, and long-press the button to zero the capacity data. Charge your phone multiple times until the mobile power turns off automatically. The next time you power on the unit, it will display the mAH output of the mobile power. Easy Data Management: To clear a set of data, press and hold the button until the capacity shows "0mAH." Quickly click the button to enter the data view mode, allowing you to cycle through and display the next set of capacity data. This feature ensures you can manage and review your data efficiently. Clear LCD Display: The UT658 is equipped with a clear LCD display that provides real-time information on USB power charging status, voltage, current, and capacity. This ensures that all critical indicators are visible at a glance, making it easy to monitor your device's performance. High/Low Voltage Alarm: The device includes a high/low voltage alarm feature. If the voltage exceeds 5.30V or drops below 4.70V, a warning sign will alert you that the output voltage is outside the normal USB 5V range. This feature helps you use your charger or mobile power safely and effectively. Enhance your charging experience with the UT658 USB Current Voltage Detector. Its user-friendly design, comprehensive data storage, and safety features make it an essential tool for anyone looking to monitor and optimize their device's charging performance.