Product name: 2.1 channel Bluetooth audio power amplifier module Product model: -HT21 Bluetooth 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: TDA7498E Adapter power supply: DC15~36V (less than 9V undervoltage protection, 12V power supply can also be supported) Adapted speakers: 30-200W, 4-8Q Output power: left and right channels less than equal 160W; subwoofer less than equal 220W Protection mechanism: anti-reverse connection, undervoltage, overheating, overcurrent, short circuit protection type:Amplifier Board Colour:black Material:plastic Size:145x126x28mm Package Contents: 1x 2.1 channel Bluetooth audio power amplifier module Only 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.