The AP1201 rechargeable silicone case with built-in battery for iPhone 4/4S is a permanent power source that extends the life of the iPhone 4/4S, providing nearly twice* the power to keep you going. It’s the power, protection & style you expect from a brand you know. Features Power Management High-speed charge direct to your iPhone or simultaneous, pass-through charge to your iPhone & case Low Profile Lightweight, flexible form-fitting silicone rubber case that is extra thin & easy to handle Protection Durable, non-slip & finger-print resistant one-piece case Reliable Integrated bumper eliminates direct contact, signal loss or antennae interference Battery Check Smart LEDs monitor power status