The speaker box uses interaction technology. Simply place a mobile device on top of the speaker, the sound from the internal speaker will be magically amplified. The item is compatible with most smart phones and has a soft rubberized finish. Simply, lay the phone down flat, screen side up and slide it around until it hits the correct spot for your phone. Phone 4S, iPhone 4, iPhone 3GS, iPhone 3GS, iPhone 3G, iPod touch 4 fit on the device perfectly. All phones work, although due to different sizes, some portions of the phone will hang off the edge Includes 3AA batteries and USB Cord.