Features Simple Operation: The key functions are rich and the operation is simple. True stepless tuning, not digital hierarchical tuning. Volume Adjustable: The volume of subwoofer and stereo output is adjusted separately; The total volume is a mechanical potentiometer, and the volume position is clear at a glance. Multi Functions: This module supports for Wuzhi Audio APP. Modify Bluetooth name, password settings, prompt volume adjustment, on, off prompt sound, lullaby, firmware upgrade, etc. Natural Sound: 10 kinds of natural sounds create unique natural sound scenes, quickly calm the mood, and achieve deep sleep. Easy to Install: Comes with a compact size and a light weight as well, the easy installation can be quickly completed. Specification: Item Type: Amplifier Board Mode: LT23 Material: PCB, Brass, ABS Purpose: Audio optimization Basic Parameters: Adaptive Speaker: Left and Right Channels: 10 to 50W, 4 to 8 Ω Subwoofer: 20 to 50W, 4 to 8 Ω Audio Output: Left channel 15W, right channel 15W, subwoofer 30W Audio Input: Bluetooth, for AUX, U disk, USB sound card Package List:1 x PCB Motherboard2 x Cover Plate4 x Brass Pillars8 x Screws3 x Knob Cover1 x Heat Sink1 x Plug1 x Screwdriver Package List 1 x PCB Motherboard 2 x Cover Plate 4 x Brass Pillars 8 x Screws 3 x Knob Cover 1 x Heat Sink 1 x Plug 1 x Screwdriver