Features: 1.Universal Compatibility: Fit for all cars and trucks with cassette players, direct use of the original car built in cassette device CD player, no modification and easy to use. 2.Bluetooth 5.1 Technology: Equipped with the latest Bluetooth version, this cassette adapter ensures stable and fast wireless connection, allowing you to enjoy music without any interruptions. 3.Low Power Reminder: When the battery is low, there is a low voltage indicator and a sound alarm, intelligent detection of tape operation, reduce the battery consumption caused by forgetting to shut down. 4.Covenient: External charging structure, convenient to listen to music while charging, better experience, ensuring hours of uninterrupted music playback on the go. 5.Wireless Music Streaming: With the Bluetooth cassette receiver, you can easily stream your favorite music wirelessly from your smartphone or other Bluetooth enabled devices. Specification: Item Type: Bluetooth Cassette Receiver Bluetooth Version: 5.1 Charging Voltage: DC 5V Signal to Noise Ratio: 90dB Shipped with built-in battery Built-in Battery Type: Button Battery Battery Model: CR1220 Individual Battery Capacity: 40mAh Note: Product is built-in battery (already installed on the product) Applicable: Fit for all cars and trucks with a cassette player