Product name: 2.1 channel 50W+50W+100W subwoofer adjustment bluetooth audio amplifierMaterial: PCB+MetalModel: -LT23 amplifier chip: domestic chipBluetooth version: 5.1. Bluetooth transmission distance: 10 meters. Audio input: Bluetooth+AUX+U disk+USB sound cardColour: blackAudio output: left channel 50W + right channel 50W + subwoofer 100WAdapter supply: DC9-24V, 5A (can not be connected to AC)Adapter speakers: left and right channels 10-50W, 4-8; subwoofer 20-50W, 4-8Volume adjustment: separate adjustment of master volume, stereo volume and subwoofer volume, wide adjustment range: master volume with buttons: single click: play/pause; double click: song; triple click: select or cancel box matching modeProtection mechanism: over temperature, over current, short circuit, anti-static protectionFeatures: Support Wuzhi Audio app. Modify the bluetooth name, password setting, volume adjustment of prompt tone, on/off prompt tone, sleep aid song, firmware upgrade, etc. box pairing function, the true wireless function enables two sets of speakers to be combined into left and right channel pairing boxes, with a sense of spatial positioning stronger.Product size: 75 x 70 x 20mm(for Wuzhi Audio APP download link:(This version of the APP is compatible with new products, please download and update the APP before using the product)http://.qingdaowuzhi.cn/btapp/Wuzhi_Audio_V1.0.3.apkLink to -LT23 product manual:http://.qingdaowuzhi.cn/ins/lt23/lt23ins.pdf)Package Contents:1 x 2.1 channel audio amplifier board1 x Screwdriver1 x DC adapterOnly 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.