4.1ch 1800 Watt Motorcycle . Snowmobile, Atv Audio System with Bluetooth (Chrome) accessories 1800 watt 4 ch motorcycle audio system, 4 waterproof speakers with handlebar clamps Audio input: AUX and RCA HI PASS adjust range : 40Hz to 400Hz Adjustable volume of Rear Adjustable volume of Front 300 watts each 4 X 3 inches Rich Texture chrome Works with any motorcycle amplifier Mirror & handle bar Brackets included fits all handlebars 7/8" 2 1/2 inches Working Voltage 10-16V DC VoiceCoil Impedance: 4 Resonc Frequency: 165HZ Effective Frequency Range: Fo-12kHZ Puiput Sound Pressure Level: 88dB Distortion: &lt;= 5% 5x6.5x2 is the size of the amplifier WxLxH (inches). Antenna for Bluetooth included