Features: 3.7V USB battery chargers cord charging cable with 51005 plugs. The charging line is equipped with an intelligent charging management chip, which can accurately charge the 3.7V lithium battery, automatically stopping when fully charge, without overcharging. The cut-off voltages at full charge is 4.23V, making reasonable use of the characteristics of lithium batteries to better extend their service life. Charging indicator: When the USB is plugged in, there is no indicator light. When the battery is connected for charging, the red light on, and when fully charge, the red light is off. Scope of application: Polymer lithium batteries, cylindrical lithium batteries, digital lithium batteries, remote control aircraft lithium batteries. Specifications: Name: 3.7V USB charging cable Material: Plastic Color: Black Protections Ffunction: overcharge protections Application Scope: Lithium battery charging Output Parameter: 3.7V 500mA Rate-power: 2-5W Plugs Model: white 2.0mm 51005 plugs Input Voltages: DC5V 0.5-2A Output Voltages: DC4.2V 500mA Package Includes: 1x USB Charging Cable note: Please allow 1-2cm errors due to manual measurement. Please allow for slight color differences due to different display resolution.