The iM54 is a compact approach to audio that offers size-defying sound. Speaker connects to a computer or other USB power source via the included USB cable to recharge the internal lithium ion battery. Remarkable design gives surprising volume and bass response in speaker that fits on a keychain. Built-in loop for clipping speaker to keychain, bag, etc. LED key light for added convenience and safety. Perfect for cell phones, iPad, iPhone, iPod and other MP3 players, any audio source.