Check the listing for details. Eminence APT50 1" High Frequency Driver APT-50, PAIR 2 pieces. Condition: New. Listed at 99.98 USD. Eminence APT50 1" High Frequency Driver The APT high-power super tweeter possesses extraordinary sensitivity thanks to a phenolic diaphragm, which has unique properties of stiffness and damping. By fluid cooling the voice coil, increased power handling, controlled low frequency behavior and long-term reliability are assured. The APT super tweeter is available as a stand-alone unit to mount on your favorite 1-3/8"-18 TPI screw-thread horn, or pre-mounted on one of three Eminence horns. Product Specifications Power handling: 45 watts RMS (crossover frequency 3.5 kHz, 18 dB/octave)85 watts RMS (crossover frequency 5 kHz, 18 dB/octave)Impedance: 8 ohms | Sensitivity: 105 dB | Fs: 2,500 HzUseable range: 3,500-20,000 Hz | Recommended crossover: 3,500 HzDimensions: Diameter: 2-3/4", depth: 2-1/2"