5/8 inch (16mm) Silk Dome Tweeters. Power Handling RMS: 100 watts per pair / 50 watts each. Ferro fluid cooled keep tweeter at a safe operating temperature. Black steel case can be flush, surface, or flex mounted. High flux lightweight neodymium magnet. All mounting hardware included. Two 12 dB Crossovers included with audiophile grade capacitors and polyswitch protection built-in. Impedance: 4 ohm. Frequency Response: 2000-22,000 Hz. Sensitivity: 90 dB