Features: brand new and high quality 2.1 Channel stereo output power 50watt x 2+100W, for working voltage range DC12-24V 4/8 passive speakers . Adopt professional ZK-MT21 module chip, with excellent sound quality. It ensures that even with high power operation for a long for time. Our Bluetooth-compatible board for amplifier audio's transmission efficiency is high and the transmission for path is wide. Support 3.5mm wired input, for high fidelity and powerful sound, with high transmission efficiency and wide transmission for path. With over-voltage for protection, under-voltage for protection, over-heat for protection, short-circuit for protection. for Ideal for DIY your passive speakers. Specifications: Product Name: Digital Power Amplifier Board Supply Voltage: DC12-24V Output Power: Left/Right Channel maximum