This is a handy charger for charging your 18650 batteries on the go! It has an 800mA output current for fast charging, and comes with a USB-to-Micro-USB cable. Plug the Micro-USB into the charger, and plug the other end into a USB port, AC adapter, car adapter, or power bank. A light indicates that charging is complete. This is a great, non-invasive option for people who frequently swap 18650s throughout the day.