Usage Tips:Mini HIFI audio power amplifier Aluminum Alloy Body, thick, feel is also very good Large knobs are designed with blue LED lights to make the products more beautiful Low distortion supplies a clearer, stronger and more powerful sound. Two main channel output, Left and right channel outputs are interfaces for speakers. Audio Sensitivity: 0.25mv-50mv Impedance: 4 - 16 ohm Signal To Noise Ratio: 85dB Out Power: 2 x 20W Number of Channels: 2 Frequency Range (Hz): 87.5MHz - 108.0MHz Frequency Response: 20Hz - 20KHz Product Weight: 200 G / 7.05 Ounces Product Dimensions(L x W x H): 115 x 95 x 45 MM / 4.53 x 3.74 x 1.77 Inches Colour: black Material: aluminum alloy Package Contents: 1 x Power Amplifier Only the above package content, other products are not included. Note: Light shooting and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.