Feature: 1. Excellent Chip: The digital amplifier module uses a TPA311D2 chip, which is known for its AM interference suppression, low interference, and excellent transfer effects. Plus, its small size makes it portable and easy to store. 2. Stable Transfer: Equipped with Bluetooth 5.1, power amplifier module offers a transfer distance of up to 10 meters / 32.8ft in an open environment and also allows for use of a 3.5 mm headphone plug. 3. Stereo Dual Channel: This amplifier module features stereo dual channel output, ensuring continuous high power working. It delivers sound through left and right channels for a stereo experience. 4. Knob Control: It allows for easy and quick adjustments of treble and bass controls through a knob. Built with PCB material, this module promises a significantly improved lifespan and simple using. 5. Special Functions: Amp module supports for BL APP, allowing users to change the Bluetooth name, set a password, adjust prompt tone volume, switch the prompt tone, use sleep music, select sound effects, and organize USB drive playlists. 6. Circuit Guards: The module is equipped with overheating guard, circuit guard, overvoltage guard, and undervoltage guard. Its high safety factor and strong practicality make it a sound choice for various sound applications. Specification: Item Type: Power Amplifier Board Material: PCB Bluetooth version: 5.1 (no blocking 10m/32.8ft) Input sensitivity: 500mV Input mode: AUX + Bluetooth + USB Number of channels: 2.0 channels Amplifier chip: TPA311D2 Applicable power supply: DC 9 to 24V Applicable speaker: 10 to 50W 4-8Ω Output power: left and right channel ≤30W ON OFF: classic mechanical switch, turn the knob to control the switch, no need to long press wait. Multi Guard: overheating, overcurrent, short circuit, anti static guards APP support: for BL. Package List: 1 x Digital Amplifier Module 1 x Top Cover 1 x Bottom Cover 3 x Knob Cover 1 x Heat Sink 1 x DC Connector 1 x Screwdriver 1 x User Manual 8 x M2 x 3 Screws 4 x M2 x 3 + 3 Copper Pillars 4 x M2 x 14 Copper Pillars