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_x000D_ Material: PCB_x000D_ Power: 15W x 2 and 30W_x000D_ Sound Channel: 2.1 Channel_x000D_ Bluetooth Version: 5.1_x000D_ Sound Input: Bluetooth, AUX_x000D_ Sound Output: Left and Right Channel, Bass_x000D_ Protection Mechanism: Electrostatic Protection, Over Current Protection, Short Circuit Protection, Over Temperature Protection, Etc._x000D_ 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