1、SIMPLE OPERATION: The main knob adopts the rotation encoder only used in high end amplifiers, realizing 360 degree infinite tuning, slick handfeel, one key start stop, long press switch on/off, simple and convenient operation. 2、PARAMETERS: Bluetooth power amplifier board adopts two TPA3116D2 chips, wide voltage input DC 12‑24V, output amplifier peak up to 50Wx2+100W (PMPO). 3、AUTO SWITCHING: If you plug in USB or AUX while playing music in Bluetooth mode, the bluetooth power amplifier board will automatically switch to AUX or USB. 4、MEMORY MECHANISM: If you used Bluetooth mode last time, this time before the amplifier board is powered on, no matter you plug in AUX or USB, the amplifier board's power on is still in Bluetooth mode. If you used AUX mode or USB mode last time, the power amplifier board will be in AUX or USB mode this time. 5、APP CONTROL: You can adjust the sound effect of bluetooth 5.0 power amplifier module, set the bluetooth name and password of the power amplifier board, and even set whether you need a beep or not through APP. Item Type: Bluetooth Power Amplifier Board Material: PCB, Aluminium Alloy Size: Approx. 113x95x25mm / 4.45x3.74x0.98in Power Supply: DC9-24V Power Supply Current (Minimum): 5A Output Power (Maximum): 50W+50W+100W Amplifier Chip: TPA3116D2 Bluetooth: Version 5.0 Sound Channel: 2.1 Sound Source: Bluetooth, AUX, Flash Disk Sound Format: (USB Flash) MP3, WAV 1 x Amplifier Module 1 x Screwdriver