1900mAh Extended Battery Charger Case Backup Power Bank with Kick Stand for iPhone 4 4S 4G Works as both an extended iPhone Battery Charger case and a protective case. Full Body Coverage for iPhone4 4S 4G. Lightweight, thin design. Non slip comfort grip. Automatic tests function. Rechargeable lithium polymer. ON/OFF Button for Optional Power Output Control. Four LED lights indicates the power level remaining the case (Each light represents 25% of remaining power)