25mm Pure Silk Dome Tweeter with 100mm Faceplate. The Monacor DT-99 is a good value replacement for old 100mm tweeters such as the Audax HD100 series, Peerless DT-100 and LR-10-DT, as found in many 1970s/80s designs. The DT 99 has an excellent radiation pattern with a smooth rising response curve and offers a level of performance that is is unparalleled at this price point. Key Features: Smooth frequency response 25mm Pure Silk Dome Wide Dispersion Good efficiency Great value for money Ferrofluid cooled Basic parameters: Resonant frequency (fs) 1500 Hz Nominal impedance (Zn) 8 Ω Effective diaphragm diameter 25mm DC resistance (Re) 5.7 Ω Ferrofluid ? Y/N Yes Max power handling 80 W Recommended crossover 2.5kHz/12dB Faceplate diameter 100 mm Sensitivity (2.83V/1m) 93 dB Cutout hole diameter 70 mm Here's the full datasheet: