Kinps&reg; for Iphone 4/4s 2300mah Lightweight Ultra-thin External Rechargeable Backup Battery Charger Case --Black 100% brand new ,back up battery case for iPhone 4/4s Used for charging your Phone anytime and anywhere Works as both an external Phone battery set and a Back up protection case Ultra-slim, sliding design and lightweight, easy to carry Two color to choose:white &black.