Features: brand new and high quality 4 audio input mode: Bluetooth-compatible / AUX / USB-C disk / USB-C sound card. App control (Sinilink-APP), it can be used to switch audio input mode / for play mode / sound effect. Left+Right channel outpu (stereo). Support active and passive speakers. Protection: anti-static , reverse polarity , short-circuit , over-heat , over-voltage , under-voltage, for DC for protection. Specifications: Material:PCB Size:60x60x16mm/2.36x2.36x0.63in Core Chip:TPA3116D2 Input Voltage:DC 5-27V / 2A Speakers Output Impedance: 4-8,10W-200W Output Power: 10Wx2@12V,8 20Wx2@12v,4; 20Wx2@18V,8 40Wx2@18V 4; 30Wx2@22V,8 50Wx2@21V,4 Bluetooth-compatible Version: 5.0 Channel Quantity: 2 (Left+Right stereo) Audio Input: Bluetooth-compatible / AUX / USB-C disk / USB-C sound card Output : LC filter output, high-definition sound quality Transmission Distance: more than 15meters (Unobstructed) Note: Please allow 0-2cm error due to manual measurement. pls make sure you do not mind before you bid. Due to the difference between different monitors, the picture may not reflect the actual color of the item. Thank you! Package includes: 1x HIFI Digital Amplifier Board