Zelta Dual USB Port Pocket Digital Multimeter Mini USB Current Voltage Power Test Meter Charger Detector DC 5V 12V 3A 30W 99999mAh Volt Amp Power Capacity LCD Display Tester Tool 4 in 1 MULTIMETER: Zelta USB voltage test meter is a highly practical testing tool for measuring voltage, current, power, capacity via your phone/USB cable or other electric device. INPUT/OUTPUT USB: Our multiple USB detector can also be a USB charger. It is compatible to all USB devices with 5V, 9V or 12V output and to devices such as iPhone, Samsung, Android, solar panel, etc. The USB signal line do not affect normal USB telecommunication. PORTABLE & HANDY: It is a portable and handy device for you to detect the quality of the power source/ USB wall charger/ USB car charger anywhere and anytime you want. RTZ: Reset button, press it three seconds will reset. SPECIFICATIONS: 2.3" x 0.9" x 0.5", 25g/pcs. Working Voltage: DC3V - 9V, Working Current: 0A - 3A.