Product name: 2.1 channel Bluetooth audio amplifier moduleProduct model: -HT21Bluetooth version: 5.0 (unobstructed, 15 meters)Input : AUX+Bluetooth+USB (switching mode and song by dial button)Number of channels: 2.1 channels (left channel + right channel + subwoofer)Amplifier chip: TDA7498EAdapter supply: DC15~36V (less than 9V undervoltage protection, 12V supply can also be supported)Adapted speakers: 30-200W, 4-8QOutput : left and right channels less than equal 160W; subwoofer less than equal 220WProtection mechanism: anti-reverse connection, undervoltage, overheating, overcurrent, short circuit protectiontype:Amplifier BoardColour:blackMaterial:plasticSize:145x126x28mmPackage Contents:1x 2.1 channel Bluetooth audio amplifier moduleOnly the above package content, other products are not included.Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.