Shark SHKMOTSUBWOOFER 6-Inch MARINE GRADE MOTORCYCLE SUBWOOFER Total harmonic distortion &amp;lt;0.5% Power supply: DC12V Hight level input: 0.4 - 8V Low level input: 0.2 - 4V Size190MM*230M Brand new &amp; factory sealed The physical size is diameter 190mm(7.48&quot;), height 230mm(9.06&quot;). This listing is for one marine grade scooter / motorcycle subwoofer. This is a very high quality unit as you can see in the pictures. 1 x 6&quot; subwoofers Frequency response: 35 - 200Hz Sensitivity: 100dB/W/m Impedance: 4 Ohm Max. output: 100W Connect the RCA cable to audio source