Features: Power amplifier board for HIFI- music. with AUX, Blue Tooth, USB flash drive, USB sound card multiple audio input methods. 5.1 Bluetooth-compatible version, the transmission efficiency is higher and more stable, the transmission distance is farther. The TPA3116D2 is a Class- D amplifier IC from TI that has very high index parameters. Advanced oscillator / PLL circuit uses multiple switching frequency options to reject AM interference. Short-circuit and thermal for protection as well as overvoltage, undervoltage, and for DC for protection to prevent total failure. TDA3116D2 is widely used in store solicitation, home theater, square speakers, etc.due to its excellent performance and comprehensive cost performance. Specifications: Size: approx 60x60x20x11mm/2.4x2.4x0.8x0.4in Power amplifier chip: TPA3116D2 BT version: 5.1 Audio input: BT +AUX+ USB disk +USB sound card Audio output: left channel 100W+ right channel 100W Adaptive power supply: DC9-24V, 5A (cannot be connected to ac Adapter horn: 20-100W, 3-80 Volume control: multi-function knob, 360 degree stepless tuning, with volume level indication. Click: for Play/pause Double click: Mode switch (BT/USB disk /AUX Long press for 1 second: on/off rotation: Adjust the volume for Protection mechanism: over temperature, over current, short circuit, anti-static for protection Features: Support WuzhiAudioAPP. Modify bt name, password Settings, prompt Sound volume adjustment, on/off prompt sound, lullaby, sound selection + custom- sound Effect, U disk playlist-, volume indicator brightness adjustment. Note: Please allow 1-3cm error due to manual measurement. pls make sure you do not mind before you bid. Due to the difference between different monitors, the picture may not reflect the actual color of the item. Package includes: 1X Amplifier Board