Specification: Item Type: Bluetooth Cassette Player Material: ABS Bluetooth: 4.2 Effective distance: about 10m/33ft (related to Bluetooth receiving device and surrounding environment) Audio channel: Left and right channel stereo Audio Input: Cassette Audio Output: Headphone Jack (3.5mm Stereo Audio Interface), Bluetooth Transmitter User Interface: Function Buttons: Play, Off, Forward fast, fast return, switch cycle, automatic return. Volume Control Button, Bluetooth Work Indicator - Blue fast flashing means matching search, slow flashing means pairing is working properly, off indicates pairing failed. Power supply: 2 x AA batteries or DC 5V USB power (this product is not supplied with batteries) Package List: 1 x Bluetooth Cassette Player 1 x USB Cable 1 x Headset 1 x Manual Note: USB Power Supply or 2 AA Batteries. (This product does not come with batteries.)