Features Stepless Tuning: This audio amplifier module can do stepless tuning, the total volume is mechanical potentiometer, the volume position is clear at a glance. 10 Kinds of Sounds: The audio amplifier module has 10 kinds of natural sounds to make you feel comfortable and build a natural feeling. Bluetooth Decoder Chip: The audio amplifier module has a Bluetooth decoder chip, supports remote firmware update, and supports true wireless stereo function. Support APP Operation: Our audio amplifier module is supported for Wuzhi Audio APP, you can modify the Bluetooth name, password setting, toning volume adjustment, on off toning, sleep song, etc. Key Function: Our audio amplifier module has many key functions and simple operation, which is very convenient to use. Specification: Item Type: Audio Amplifier Board Module Model: LT22 Material: PCB, brass, ABS Use: Audio optimization Basic Parameters: Adapted Speakers: Left and right channels 10 to 30W, 4 to 8Ω, Subwoofer: 10 to 30W, 4 to 8Ω. Audio Output: Left channel 15W and right channel 15W and subwoofer 30W Audio Input: Bluetooth and AUX and U Disk and USB sound card Package List:1 x PCB Motherboard2 x Cover Plate4 x Copper Column8 x Screw3 x Knob Cover1 x Heat Sink1 x Plug1 x Screwdriver Package List 1 x PCB Motherboard 2 x Cover Plate 4 x Copper Column 8 x Screw 3 x Knob Cover 1 x Heat Sink 1 x Plug 1 x Screwdriver