iPHONE 4 Case with Sound Enhancer Plus Battery Charger HD

You can purchase it in ebay, just search for iPHONE 4 Sound Amplifier Enhancer / Battery Charger and Case Protector Aifone Main Functions: - All-round Protection of mobile phone, anti-knock and anti-falling - A built-in 1500mAh battery doubling the endurance of mobile phone - A built-in subwoofer speaker amplifying sound volume by 10 times - The back prop making the mobile phone lying on its side and position adjustment available - GPS navigation, as a speaker, contributing to clearer sound - Good New Year Gift Manufacturer Specifications: - Material: Hard Molded ABS - Capacity: 1500mAh - Charging Time: 3-5 hours - Conversation Time: More than 5 hours - Audio Play: More than 20 hours - Video Play: More than 5 hours - Speaker Amplifier: 10W+5W - Output Voltage: DC5 ± 0.1V - Output Current: ≤ 700mA (0.7A) - Input Voltage: DC5 ± 0.2V - Input Current: ≤ 500mA (0.5A) - Dimensions: 125 x 60 x 19 (mm) Package Contents: - iPhone 4/4S Charging Case - 1500 mAh Rechargeable Battery - User Manual - English / Chinese