While most emphasis in a car stereo is on bass and sub-bass frequencies, a high-quality car audio system features a proper balance over entire range of audio frequencies. Improve the upper end of your car audio system by installing these 25mm Car Audio Tweeters from Monoprice! These tweeters feature a 25mm silk-cloth driver and a 4-ohm nominal impedance (�15%). They are rated for frequencies between 1.8 ~ 20 kHz and produce 84 �2dB Sound Pressure Level at 2~6 kHz. Each tweeter mounts into a round hole with a 1.9" diameter and 0.6" (14.5mm) depth. Each order includes two (2) tweeters. 30-day easy returns. No restocking fee. Free lifetime technical support. 1 year warranty.