Features: brand new and high quality Input: Bluetooth-compatible+AUX+U Disk+USB Sound Card. Audio output: left & right channel+subwoofer + 3.5mm interference interface stereo. Stereo Dual-channel Output to Ensure Continuous Serial High-power Operation. It has short-circuit for protection, over-current, over-heat, and anti-reverse for protection. When an overload occurs, the device reports the fault condition to the processor to protect itself from damage. Special function: support YS Audio-app operation. Specifications: Material: metal Length: approx 95mm/3.7in Width: apporx 88mm/3.5in Height: approx 2.8cm/1.1in S/N Ratio: 95dB Power supply: for DC 5-26V/10A or above Bluetooth-compatible Version: 5.0 Channel: 2.1 channel Input: Bluetooth-compatible+AUX+U Disk+USB Sound Card Output: Left and Right Channels + Subwoofer + 3.5mm Stereo Port Frequency Range: 20HZ--30KHZ Output Power:50W+50W+100W Note: Please allow 1-3cm 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. Package includes: 1x Amplifier Board