EasyAcc&reg; Ultrathin Lightweight 3-in-1 Charger for Samsung Galaxy S3 S4 Comes with USB Output 3-in-1: Charges Samsung Galaxy S3 and S4 batteries by simply adjusting a flap and works as an external battery when a S3 or S4 battery is inserted by using the USB output. Innovatively designed: Ultrathin and lightweight (just 11 mm thick), making it convenient for you to take around. LED indicators: 4 built-in LED indicators keep you informed of the charging status at all times. Safe to use: Designed specfically for Samsung mobile phone batteries and certified by CE, FCC, and RoHS, ensuring a safer and more efficient charging process. Worry-free after-sales service globally: EasyAcc provides a 12-month warranty and free lifetime technical support.