Features: Brand new and high quality Bluetooth-compatible 5.0, support serial port to change the name and password. Support button shutdown/boot, support serial port to change the volume and off, power on by fault, no call function, the default volume is the largest. Board and device, excellent workmanship, material and reliable quality. DC8-26V power supply with reverse connection protection, support for laptop power adapter. At 24V4A, the maximum output power is 2x30W, power varies with voltages. Specifications: Material:PCB Suitable impedance: 4/6/8ohms Board Size: Approx.8.5x5.2cm/3.34x2.04inches Fixed hole Distance: Approx.7.9x4.6cm/3.11x1.81inches Note: 1.Please allow 1-2cm errors due to manual measurement, make sure that you do not mind before you order. 2.Due to the difference between different monitors, the picture may not reflect the actual color of the item. Package includes: 1x Power Amplifier Board