Music volume adjustment: Multi-Function buttons Click: Play/Pause; Double click: Next track;Triple Strike: Previous song;Long : Mode switch MIC volume adjustment: Multi-Function buttons Click: Suppress Voice Long : Enter or exit mode. Indicator light status: The blue light flashes slowly in USB and AUX modes, the BT connection is successful and stays on, and it flashes extremely slowly when there is no connection. Start , red light flashes to search for pairing, red light stays on left channel, red light flashes slowly right channel. Mode priority: Inserting a USB flash drive or AUX can steal BT, and the mode can be remembered after power failure. BT cannot be found in USB or AUX mode. Protection mechanism: 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.<br><br>Product model:-1001UM Product name:Mono 100W BT amplifier module with microphone reverb Amplifier chip:TPA3116D2 BT version:5.3 BT transmission distance:15m Audio input:BT+AUX+USB disk+Microphone Audio output:Mono 100W Adaptive power supply:DC9-24V, equal 4A (cannot be connected to AC power), suitable for batteries such as 7.4V12V21V, not suitable for 24V batteries, fully cause overvoltage. Adaptive speaker:20-100W, 3-8 Product size:99x75x22.8mm Color:Black Material:Metal+Plastic<br><br>Package Contents: 1 * BT amplifier module<br><br>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.