DFRobot Stereo Bluetooth Amplifier Board is a small size and cost-effective module with a volume adjustment function. The board connects to two speakers and matches a wide variety of high-power speakers (40W-200W). The Stereo Amplifier Board can be used as a small Bluetooth speaker when connected to Raspberry Pi or mobile phone. It offers excellent two-channel stereo sound effects. The board comes with power supply reverse connection protection, and short circuit protection. Note: Speakers sold separately. Features & Specs * Voltage: 5-24V * Bluetooth 5.0 * Transmission Distance: 15m (visible) * Sound Channel: two channels (stereo) * Match Speaker: 4Ω（5~16V), 8Ω（5~24V) * Output Power(@1KHz): * 20Wx2 @12V 4Ω * 30Wx2 @16V 4Ω * 30Wx2 @21V 8Ω * 40Wx2 @24V 8Ω