DF Store Durable OLED USB Charger Capacity Power Current Voltage Detector Tester Meter Brand new and high quality. Accurate reading error is small does not bounce and other significant advantages. This product is all original device SMD chip technology, fine workmanship, excellent performance and reliable products. Support both positive and negative angle display. 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 to judge the performance of the charging cable charging equipment is meet the requirements!