100W*2+200W 2.1-channel Bluetooth digital amplifier, dual-core TPA3221. Add power switch, safer; lossless components, better sound quality; independent tuning of high and low frequencies, more convenient. Quality first, exquisite materials. Dual core is more stable, using 2 for original-imported TPA3221 amplifier chips. TPA3221 chip audio power core, high efficiency, low power consumption, high-definition sound quality and comprehensive protection mechanism. XY-ST21PRO Bluetooth antenna interface, the first generation IPEX interface has been welded, and an external Bluetooth antenna can be connected. Note:self-assembly is required. Type:B:With shell/A:Bare board/C:Potentiometer external connection Colour:Black Material:Plastic Package Contents: 1 * digital Audio power amplifier Board Only the above package content, other products are not included. Note: Light reflection 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.