1. This product is very suitable for DIY simple mono amplifier, with built-in boost circuit, very suitable for upgrading or making battery-powered outdoor speakers, pull-rod speakers, and mobile speakers 2. Support APP, modify Bluetooth name, password setting, prompt sound volume adjustment, on/off prompt sound, sleep music, firmware upgrade, etc. 3. 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 4. Protection mechanism: input anti-reverse connection, over-temperature, over-current, short circuit, anti-static protection 5. APP has a timer shutdown function Colour:black Material:PCB+Components Model: -1001U Name: 100W mono Bluetooth amplifier board module with boost and bass and treble adjustment 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 Applicable power supply: DC9-24V, 4A (not connected to AC), suitable for 7.4V12V21V and other batteries, not suitable for 24V batteries, full charge cause overvoltage Applicable speakers: 20-100W, 3-8 Due to different batches, there may be differences in product appearance and printed text, which not affect use Package Contents: 1 * Bluetooth Amplifier Board Kit 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.