Customized senior shielding inductor approved by audiophiles in popular forums, improving the most important LC filtration procedure for digital amplifiers The Bluetooth Hi-Fi wireless connection uses top British CSR 4.0 Bluetooth module, ensuring high-quality audio transmission With FM function, you can listen to the music any time and any where Compatible with car, motorcycle, Mp3, computer speaker and other audio applications AUX high fidelity audio frequency inputs and easily connects to an extensive audio-visual product of CD / DVD / PC etc. Real 2RMS x 20W stereo circuit design Built-in circuit for speaker protection and start delay, ensuring that there is no impact sounds upon shutdown / start up and that your valuable speaker would be well protected ( speaker will be included in the circuit 3 seconds after start up ) Name: Model Number:-502S Input power: DC 12V Speaker impedance: 4 - 8ohms Frequency response: 20Hz - 20KHz Total harmonic distortion: more than 0.05 percent Sound