Features 1.2.1 CHANNEL: Sound power amplifier board has 2.1 channel stereo output, output power 15Wx 2 and 30W, HiFi audiophile sound quality, treble pure and transparent, bass surging shock. 2.KNOB ADJUSTMENT: Power amplifier module uses a special high end coding knob adjustment to achieve 360 degrees of continuous tuning, support a key to start and stop, long press to switch the machine. 3.APP CONTROL: Bluetooth power amplifier board supports for YS APP control, visual playback mode support for iOS and for Android system, support Bluetooth, support to modify the name, set the connection password, volume, play pause, etc. 4.COMPATIBLE DEVICES: Digital power amplifier board has a variety of input and output modes, compatible with almost all home devices, such as smart phones, MP3, PC, TV, tablets, laptops, etc. 5.MULTI PROTECTION: Bass power amplifier module has a built in multi protection mechanism with electrostatic protection, overheating, over current and short circuit protection. specificationItem Type: Sound Amplifier Board Material: PCB Power: 15W x 2 and 30W 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 for YS APP Control PackageList1 xSoundAmplifierBoard 2 x Cover Plate 3 x Knob Cover 1 x Heat Sink Block 1 xAdapter 1 x Screwdriver 4 x Golden Screw Post 8 x Black Screws