The BT90S is a heavy duty titanium bullet tweeter. It efficiently hits highs and mids and can adapt to any system. Sold and priced per piece. Features: Titanium dome Ferrofluid cooled Diecast aluminum housing Kapton voice coil Crossover capacitor included Specifications: Power Handling: 300 Watt Nominal Impedance: 4 - 8 ohm Frequency Response: 3kHz - 20kHz Sensitivity: 110dB Fs: 6500 Hz