Give your iPhone 3G 3GS up to 10db audio amplification with the Griffin AirCurve Acousitc Amplifier for iPhone3G 3GS. With an ingenious design and a special pass-through slot for the USB Sync/Charger Cable for iPhone/iPod Touch, the Griffin AirCurve requires no power or any installation - just plug and play with the AirCurve Acousitc Amplifier and the iPhone USB charger