Peak: 210 watts per pair / RMS: 70 watts per pair Plus One polypropylene cone Rubber speaker surround Balanced dome tweeter 2.3 ohms Nominal impedance External Diameter: 4.125" Cutout Diameter: 3.75" Total Depth: 2.60" (top of tweeter) Frequency Response: 75 - 21,000 Hz Sensitivity (2.8V/m) : 90 dB