Function: 1. Just plug the cassette adapter into your car's CD player, then the cassette adapter starts playing music on your phone. 2. The built-in microphone can support the calling function without delay in making and receiving calls. 3. Cassette adapter with USB charging LED indicator is convenient for charging. 4. The control button box adapter can be easily controlled by hand, easy to operate. 5. The tape converter with bluetooth 5.0 technology allows you to conveniently play music on your smartphone via bluetooth connection. Specification: Item Type: Car Bluetooth Cassette Adapter Material: ABS plastic Color: Black Product Size: Approx. 10 x 6.4 x 0.9 cm / 3.9 x 2.5 x 0.4 inch (There is an error due to manual measurement) Bluetooth Receiving / Connecting: Support Audio format: AAC, MP3, for SBC, stereo Bluetooth support: 5.0 and EDR Indicator light : blue, red Transmission distance: approx. 10 m / 32.8 ft Built-in battery: 140mAh lithium battery Charging current: 80mA Operating voltage: 3.3-4.2V Charging input voltage: 4.5V-5.3V Output Mode: Bluetooth How to use: Just plug the cassette adapter into your car's CD player. Then the cassette adapter will start playing music on your phone. Package List: 1 x Cassette Adapter 1 x charging cable 1 x Manual