Feature 12.1 SOUND CHANNEL: 2.1 channel Bluetooth amplifier board with 2.1 channel, Bluetooth 5.1, AUX, APP new upgrade. aux sound input shocking sound. 2APP VISUAL OPERATION: APP visual operation play mode volume, sound, up and down song control, play pause, play mode to modify the Bluetooth name, set the connection password. 3MOBILE APP CONTROL: Bluetooth amplifier board is controlled by cell phone APP, support for Android for iOS system, the transmission distance is longer. 4SECURITY PROTECTION: Bluetooth power amplifier board has static protection, over current protection, short circuit protection, and overheat protection. 5ENCODER KNOB ADJUSTMENT: 2.1 channel Bluetooth power amplifier board supports high end encoder knob adjustment, AUX sound connection left and right channel.Item Type: 2.1 Channel Bluetooth Power Amplifier BoardMaterial: PCBBluetooth Version: 5.1Sound Channel: 2.1 ChannelInput Method: Bluetooth, AUXSound Output: Left And Right Channel, Bass ChannelPower Supply: DC12-24VVolume Adjustment: High End Encoder Knob Adjustment, Fluent FeelFrequency Range: 20Hz-30KHzSignal To Noise Ratio: 92dBOutput Power: 2 x 15W (Left And Right Channel), 30w (Bass Channel)Satellite Box (Left And Right Channel) Adaptable Speakers: 5W-30W 4-16Bass Channel (Subwoofer) Matching Speakers: 5W-50W 4-8Protection Mechanism: Electrostatic Protection, Over Current Protection, Short Circuit Protection, Overheating ProtectionAPP Function: Support APP Control .wang-edit-text{ font-family:'Arial' !important; } .wang-edit-text table { border-top: 1px solid #000; border-left: 1px solid #000; } .wang-edit-text table td, .wang-edit-text table th { border-bottom: 1px solid #000; border-right: 1px solid #000; padding: 3px 5px; } .wang-edit-text table th { text-align: center; }Package List1 x 2.1ChannelBluetoothPowerAmplifierBoard1 x Upper Cover Plate1 x Lower Cover Plate3 x Knob Cap4 x M2x3mm Screws4 x M2x16 Brass Post4 x M2x8 Screws1 x DC Adapter1 x Screwdriver1 x Heat Sink