Feature: 1. Sound Control: If you're tired of the inherent highs and lows, why not try the treble and bass control knobs! This will give you the feeling of being in a movie theater. 2. Long Transmission Distance: The module uses Bluetooth version 5.0 for longer transmission distance, up to 33 feet in an open environment. 3. Basic Performance: Stereo dual channel output ensures continuous serial high power operation with THD ≤ 0.1%, wide voltage input DC12‑24V. 4. 3.5mm Jack: If your playback device does not have Bluetooth, you can also input audio signal through the 3.5mm headphone plug. 5. Safety Protection: This audio amplifier board has overheat protection, circuit protection, overvoltage and undervoltage protection. Specification: Item Type: Audio Power Amplifier Board Material: PCB Bluetooth Version: 5.0 (unobstructed, 10m) Signal to Noise Ratio: >90dB Input Mode: AUX and Bluetooth Number of Channels: Left and right dual channel (stereo) Power Amplifier Chip: TPA3116D2 (with AM interference suppression function) Power Supply: DC 12-24V, 5A or more (the higher the voltage, the higher the output power) Applicable Speakers: 20-200W, 4-8 Ω Output Power: 2 x 20W at 12V,8Ω, 2 x 35W at 12V,4Ω, 2 x 35W at 19V,8Ω, 2 x 60W at 19V,4Ω, 2 x 50W at 24V,8Ω, 2 x 100W at 24V,4Ω Protection Mechanism: Overvoltage, undervoltage, overheat, DC detection, short circuit protection. Package List: 1 x Audio Power Amplifier Board3 x Rotation Knob1 x Screwdriver2 x Protective Shell8 x Screw8 x Nut