DigiEspow FM Transmitter + Car Charger + Holder for iPhone 4 4S Hi-Fi Stereo FM Transmitting at 88.1-107.9MHz (0.1MHz/step) brings you the perfect music enjoyment iPhone Hands-free supports talking through car speaker system; 3. Supply charging power for iPhone and iPod models with dock connector Flexible Goose-pipe makes it convenient to find the best position for your devices with any car in the world; 5. Goose pipe rotation-preventing design makes the iPhone/iPod devices steady and secure Standard USB-A (5V, 1A) output socket provides the charging for iPod Shuffle, Microsoft Zune, mobile phones, GPS and other portable devices Using a flexible clamp to fix the iPhone/iPod steadily in the car. Removable stoppers prevent it from dropping.