Tape with strong Bluetooth function, insert the cassette into the car cassette player, then connect it to your phone via Bluetooth to enjoy music and hands-free calling. Built-in microphone supports hands-free calling, easily answer or end a call with one button. No need to hold the phone while driving. Features the latest Bluetooth 5.0 chip for stable performance, clear calling quality, wide compatibility, and continuous stereo music playback. The cassette includes USB ports and a built-in 130mAh rechargeable battery, safe and durable. Charge the device using a power bank, laptop, or any USB adapter. Ideal for use in cars and vehicles to enjoy music and hands-free calling. Bluetooth version: 5.0. Power supply: USB. Battery: built-in 130mAh rechargeable battery. Size: 10 x 6.3 x 0.7cm / 3.93 x 2.48 x 0.27inch. Weight: 62g. Color: Black. Material: ABS. Package includes: 1 x cassette adapter, 1 x USB cable. Only the items listed are included. Note: Light reflection and display differences may cause slight color variation. Measurement error allowed is +/- 1-3cm.