With this cassette to MP3 converter,you can easily convert your old tape to MP3 without a computer you just need to plug a USB Flash disk(or USB card reader with SD card)on then "record"button and the device convert all of the music on tape to your USB Flash disk in MP3 format automatically.You can also playback on it,or just put USB Flash to other place (computer,portable speaker,or transfer to your mobile phone,,etc.)to play the recorded music. Power supply:1,You can simply use the USB cable in the package to power supply this device.2,You can also use 2xAA batteries(not including)----Open the lid of the deck, and put batteries in the groove. Operate:Put a cassette in. Connect a speaker or earphone to"Headphone jack"of the device. Connect an USB disk to"OTG",you see indicator lights. "PLAY"button of the top,you should hear the sound from the cassette playing. Turn the volume switch to a level you favor (usually be max is ok) NOTE:For save energy, the convert circuit only work when an USB disk be connected. You can still play cassette even without USB disk. Color: As Shown Material: Plastic Package Contents: 1 x Cassette Converter (without 2xAA batteries,You need to prepare yourself) Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.