Features: 1. 100% brand new and high quality. 2. With internal power supply isolation, avoiding the current noise generated between the receiver box and post-amp, more suitable for car modification. 3. You can pair your phone with this audio receiver via Bluetooth to have hands-free phone calls and listen to music. 4. 5V supply voltage, can be powered by phone charger, power bank, computer USB interface, etc. 5. With USB decoding play and TF card decoding play function. Specification: Model: HF54 Options: With isolation, without isolation Audio input mode: Bluetooth receiver, USB decoding play, TF card decoding play, 3.5mm headphone audio input Supporting play format: MP3, WMA, WAV, FLAC Power supply: DC 5V Audio output mode: 3.5mm audio preampl output, post-amp audio input, can also directly drive headphones Package weight: Approx. 55-58g Package list: 1 * Bluetooth Audio Receiver Box 1、100% brand new and high quality. 2、With internal power supply isolation, avoiding the current noise generated between the receiver box and post-amp, more suitable for car modification. 3、You can pair your phone with this audio receiver via Bluetooth to have hands-free phone calls and listen to music. 4、5V supply voltage, can be powered by phone charger, power bank, computer USB interface, etc. 5、With USB decoding play and TF card decoding play function.