Features: brand new and high quality The use of high-speed SMTplacement machine,over temperature reflow, the performance is very stable. With 4 model GAINparts.can auto work on different-voltage. Ultra-small 70x57mm.Comes with super output short-circuit and over-temperature over-load and prevent the impact of the switches machine. It can be used to repair and polish active speaker and improve sound quality. It can also use multi-blocks multi-channel power amplifier or 2.1 power amplifier, which has many uses. Low-price.but with high-power and good sound quality output. Specifications: Material:Metal Power supply: Single-voltage 10-26V Maximum power:50Wx2/8Ohm Size:Approx.70x57mm/2.76x2.24inches Note: 1.When the horn impedance is 4ohms, the working-voltage must be less than 18V, when the horn impedance is 6ohms, the working-voltage cannot exceed 24V, and when the horn impedance is 8ohms, the working-voltage cannot exceed 26V, and the polarities of power supply should not be reversed. 2.Please allow 1-2cm errors due to manual measurement, make sure that you do not mind before you order. 3.Due to the difference between different monitors, the picture may not reflect the actual color of the item. Package includes: 1x Power Amplifier Board