30pcs USB Tester Current Voltage Charger Capacity Tester Volt Current Voltage Meter Mobile Power Detector Battery Test Wholesale  Features:  100% Brand New and High Quality  This is the mini USB meter. It can measure voltage, current, power and capacity  It can clearly display all the data  Can easily measure the USB ( PC USB, cell phone charger, car charger , mobile power , etc. ) port and device operating current and the output voltage charge-discharge capacity,performance, and judge the performance of the charging cable charging equipment, this tester can meet the requirements  Fit to factories, laboratories and personal use, wide range and Easy to use, easy to take alone, no additional power supply, Plug and play.  Specifications:  Material: Plastic  Color: Black  Voltage: 3-9V+/-1%  Current: 0-3A+/-1%  Time: 0-99H  Net weight: 19g                Packing Includes:  30 x Current Voltage Capacity Tester  NOTE:   This item come without retail package and it will have KEWEISI on that usb Brand:keweisi  (this product brand is KEWEISI,not JUANJUAN,please kindly note it )