- 2,200 mAh lithium polymer ZiLu smart battery, rechargeable for over 500 cycles. - Intelligent battery management technology increases iPhone run time by more than 200%. - More power per milliamp hour (mAh) than other technologies in a thin, lightweight and protective case. - Allows iPhone to charge and sync while in the ZiLu smart battery case. - Built-in short-circuit, overcharge, over discharge, energy flow back, and malfunction protection. - Case is built to exact specifications to provide secure fit and proper function of iPhone. - High-quality leather offers distinctive, yet durable, looks. - Openings for iPhone charge port, microphone, speaker, camera, and proximity sensor. - Available in a variety of different style, color, and leather combinations. - Magnetic closure on side secures the case in the open and closed positions. - ZiLu craftsmanship and quality guaranteed.