Features: Adopt TPA3116D2(with AM interference suppression function) chip, with excellent sound quality. It ensures that even with high power operation for a long for time, THD is less than 0.1%. 2 Channle stereo output power 50watt x 2, working voltage range DC5-27V, for 4-8Ω, 50watt-200watt passive speakers. This amplifier board supports 3.5mm wired input and Bluetooth-compatible 5.0 input. Bluetooth-compatible signal distance up to 49ft. With volume control and power switch, for Ideal for DIY your passive speakers. This Bluetooth-compatible amplifier board has a bottom plate and a top plate, support reverse connection for protection, Over-voltage for protection, under-voltage for protection, Over-heat for protection, Short-circuit for protection. Specifications: Material:Metal Color:Black Work Voltage: for DC 5V-24V (Above 2A) Channel: 2 for CH Stereo Output Bluetooth-compatible Transmission Distance: 50 Ft MAX Power Output: 50W x 2 Treble and control: Yes Terminating Impedance: 4 - 8 Ohm Match Speaker: 50 - 200watt Work Humidity: 0%~95%RH Package Includes: 1x Wireless Amplifier Receiver Board note: Please allow 1-2cm errors due to manual measurement,pls make sure that you do not mind before you order. Due to the difference between different monitors, the picture may not reflect the actual color of the item.