Efficient connection: With a transmission distance of up to 15 meters, it supports multiple input methods such as BT, AUX, USB flash drive, and USB sound card. Built in boost circuit: compatible with DC9-24V power supply, especially suitable for outdoor and mobile speakers powered by batteries. Multi functional button control: One click to play/pause, switch tracks, power on/off, and enter mode, easy to operate. Powerful box function: Two sets of equipment can be combined to create left and right channel stereo sound, with strong spatial positioning and suitable for DIY production. Intelligent protection mechanism: equipped with anti reverse, over temperature, over current, short circuit, and anti-static protection to safe and stable use. Featured feature: Supports APP. Modify BT name, password settings, adjust the volume of prompt sound, turn on/off prompt sound, sleep aid music, firmware upgrade, and more. function and true wireless function allow two sets of speakers to be combined into a left and right channel box, providing a stronger sense of spatial positioning. After interconnection, two speakers instantly become left and right channel stereo speakers, achieving true wireless connection. Product model: 1001U Product Name: Single channel 100W BT amplifier module with boost and high/low frequency adjustment Amplifier chip: TPA3116D2 BT version: 5.3 BT transmission distance: 15 meters Audio input: BT+AUX+USB flash drive+USB sound card Audio output: Mono 100W Suitable power supply: DC9-24V, equal 4A (cannot be connected to AC power), suitable for 7.4V12V21V and other batteries, not suitable for 24V batteries, fully cause overvoltage. Compatible speaker: 20-100W, 3-8 Volume adjustment: Total volume with buttons Click: Play/Pause Double Click: Next Three Click: Enter or Exit T W S Mode Long : Power Off/On Protection mechanism: Input anti reverse, over temperature, over current, short circuit, anti-static protection Product size: 99x75x22.8mm Box function: This function requires the purchase of two sets of amplifier boards to form a box. This product is very suitable for DIY simple mono amplifiers, with built-in boost circuits, and is very suitable for battery powered outdoor speakers, telescopic speakers, and mobile speakers for upgrading, modification, or production. The circuit board printing is slightly different, which does not affect the use. Colour:As Shown Material:PC Package Contents: 1 x amplifier board (heat sink and knob cap need to be installed by oneself) 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.