Cool knight&reg; 2pcs 2600mah battery with dock charger for Samsung galaxy S4/I9500 2pack 3.7v DC 2600mah rechargeable lithium-on battery The battery is built in protection systerm,over current,over charge,over discharge protection The intellgent charger built in protection systerm,stable and reliable,and secure Special for Samsung galaxy S4/I9500 Package:2* batteries,1*Dock charger