Protection Function: 1. Input Overcurrent Protection 2. Output Current Protection 3. Short Current Protection Application: Suitable for lithium batteries (lithium ion batteries, lithium polymer batteries), battery pack rated voltage is 18.5-21V, capacity range is 1100-5500 mAh. For example, 18650 18490 14650 14514430 and other batteries. Specifications: Input voltage: AC100-240V//50/60Hz Output voltage: DC21V Output current: 2A Plug: EU, US Cable length: about 0.9 meters/2.95ft DC plug: 5.5x2.5mm, compatible with 5.5x2.1mm Polarity: positive inside and negative outside Weight: about 100 g When charging, the red light is on, the green light is on when full charging, and the charging stops automatically. Note: Please allow 1-3mm differs due to manual measurement. Due to the different display and different light, the picture may not show the actual color of the item. Thanks for your understand. Packages: 1 X Power Adapter Charger