Dopo Mini Bluetooth Keyboard for Smartphones, iPad, iPhone, PS3, Windows - Black (PA-BK03) Compatible with: Android OS, Nokia Symbian OS, Windows Mobile OS, iPhone 4 OS Mini Bluetooth Keyboard for Smartphones, iPad, iPhone, PS3, More Battery Duration: Constant Use: ~50 hours; Standby: ~400 hours; Power: Charges by USB; Charging Time: 3-4 hours Pocket sized and portable with a sleek, slim design Ideal for typing emails and chatting, and gaming Compatible with: Android OS, Nokia Symbian OS, Windows Mobile OS, iPhone 4 OS Mini Bluetooth Keyboard for Smartphones, iPad, iPhone, PS3, More Battery Duration: Constant Use: ~50 hours;Standby: ~400 hours;Power: Charges by USB; Charging Time: 3-4 hours Pocket sized and portable with a sleek, slim design Ideal for typing emails and chatting, and gaming