NOSTeck 3200mAh iPhone 4 4S 4G Battery Charger Case External Rechargeable Backup 3200mAh 3200mAh External battery charger case for iPhone 4 / 4s. Brand new and high quality, Light Weight, Ultra thin fashion design. 4 LED lights indicates the power level remaining the case (Each light represents 25% of remaining power) Works as both an extended Phone battery set and a protection case. Warranty:1 year warranty