These Woofers Qty of One (1) AR#200003-0 are original AR3a Woofers Mfg Nov 15th 1972 and Oct 21 1972 (Stamped on Magnet), Made in the USA, both have been foamed and fully functional. The Meter resistance reading are DCR Ohms and IMP Ohms respectfully. They were removed from AR3a 1972 Vintage speakers. Woofer : 12-inch (305 mm). Impedance : 6 ohms nominal (Measured at 1000Hz) Resistive : 2.7 Ohms nominal (Measured). Woofer resonance : Free air 18 Hz verified! , in enclosure 42 Hz (AR3a Specs).