Product name: 2.1 channel 15W+15W+30W subwoofer adjustment bluetooth audio amplifierModel: -LT22 amplifier chip: domestic chipBluetooth version: 5.1Bluetooth transmission distance: 10 meters.Audio input: Bluetooth+AUX+U disk+USB sound card. Audio output: left channel 15W + right channel 15W + subwoofer 30WAdapter supply: DC9-24V, greater than equal 3A (can not be connected to AC)Adapter speakers: left and right channels 10-30W, 4-8ohm; subwoofer 10-30W, 4-8ohmVolume 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: 75x70x20mm(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 -LT22 product manual:http://.qingdaowuzhi.cn/ins/lt22/lt22ins.pdf)Colour:blackMaterial:PCB+MetalPackage Contents:1 x 2.1 channel audio amplifier board1 x Screwdriver1 x DC adapter1 x DC cableOnly 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.