Wide Applicability: This USB Power Meter measures voltage: 4V-30V; measures current: 0-6.5A. Supports QC2.0, QC3.0, iPhone 2.4A/2.1A/1A/0.5A, Android DCP/AFC, FCP(9V/2A)/SCP(4.5V/5A), Super VOOC fast charging protocol identification, letting you know your phone's charging status. Supports high-current testing, supports USB3.0 interface mobile hard drive and U-disk testing. Power-Off Storage, Measurement Data Guaranteed: This USB tester features a power-off storage function, which can store capacity and power data when the mobile power supply is turned off, convenient for subsequent viewing and facilitating the measurement of the mobile power supply's capacity and power. IPS LCD Screen: Uses a 0.96-inch IPS high-resolution color LCD screen to display the device's charging status, voltage, current, capacity, energy, power, equivalent impedance, temperature, and other indicators at a glance. 4-bit accuracy for more precise measurements. Note: The button on this product will make a sound when shaken, which is not a product defect. This is an adjustment to be made to quickly double-click the button, which is a normal situation.