Russound RSF-610 6.5-Inch Acclaim Performance Speaker, Magnetic Edgeless Grille (Black) - Set of 2 6.5" polypropylene woofer withNBR surround 3/4" Ferrofluid-cooled, pivoting PEIdome tweeter Frequency range: 50Hz-20kHz Sensitivity: 88 dB Nominal impedance: 8 ohm