Amplifier chip:TPA3116D2 Bluetooth version:5.3 Bluetooth transmission distance:15 meters Audio input: Bluetooth + AUX + U disk + USB sound card Audio output: mono 100W Product model:-1001U Product name:100W mono Bluetooth amplifier board module with boost and adjustment Adaptive power supply:DC9-24V, equal 4A (not connected to AC power), suitable for 7.4V12V21V and other batteries, not suitable for 24V batteries, full charge cause overvoltage. Adaptive speakers:20-100W, 3-8Ω Volume adjustment:total volume with button Single click:play/pause Double click: next song Triple click: enter or exit mode Long : power off/on Protection mechanism: input anti-reverse connection, over-temperature, over-current, short circuit, anti-static protection Featured functions: support APP. Modify Bluetooth name, password setting, prompt volume adjustment, on/off prompt tone, sleep music, firmware upgrade, etc. Pairing function, true wireless function allows two sets of speakers to be combined into left and right channel pairing, with a stronger sense of spatial positioning. Product size:99x75x22.8mm Product weight:net weight 328g Colour:Black Material:ABS Package Contents: 4 x 100W Bluetooth amplifier board Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.