This iPhone 4 battery can serve as a protective case and a FM transmitter for added functionality. It is constructed from quality ABS material for a long service time. This heavy-duty iPhone FM transmitter battery makes a supreme choice for iPhone 4 owners.

• Material: ABS.
• Capacity: 1,900mA (Li-Po1).
• Input: 5V/500mA.
• Output: 5V/1A.
• FC, CE and CCC compliant.