5.25” 2-way Indoor/Outdoor Speaker Woofer: 5.25” Aluminum cone, rubber surround, 18.5oz Magnet, 1" voice coil, bumped back plate Tweeter: 25mm Aluminum dome, Ferro-fluid cooled, Ferrite magnet, wide dispersion Crossover: Phonalic PCB board, 6dB woofer section, 12dB tweeter section, Polymide auto protective switch for tweeter General Data: Frequency Range 60Hz- 20KHz Sensitivity 87dB Recommended Amplifier Power 10-80 watts Nominal Impedance 8 ohm