Features 1.Superior Sound Quality: Bluetooth amplifier board supports 2.1 channel stereo output, output power 50w, 500w, 100w, audiophile sound quality, treble pure and transparent, bass surging shock. 2.Knob Adjustment: Classic appearance of the multi functional main knob, support a key to start and stop, easy to operate. The use of special high end coding knob adjustment, to achieve 360 degrees of continuous tuning. 3.APP Control: Digital amplifier board supports cell phone APP control, the new upgraded APP sound control, visual playback mode support for ios for for Android system, support Bluetooth. 4.Wide Compatibility: Amplifier board has a variety of input and output modes, compatible with almost all home devices, such as smart phones, MP3, PC, TV, tablet PCs, laptops, etc. 5.Safety Protection: Amplifier board has static protection, overheat, overcurrent and short circuit protection. Support name modification, set connection password, volume, play pause, etc. specificationItem Type: Digital Amplifier Board Material: PCB Power: 50W, 500W, 100W Sound Channel: 2.1 Channel Bluetooth Version: 5.1 Sound Input: Bluetooth, AUX Sound Output: Left And Right Channel, Bass Protection Mechanism: Electrostatic Protection, Over Current Protection, Short Circuit Protection, Over Temperature Protection, Etc. Special Features: Support APP Control PackageList1 x DigitalAmplifierBoard 2 x Cover Plate 3 x Knob Cover 1 x Adaptor 1 x Screwdriver 4 x Golden Screw Post 8 x Black Screw