Model Silk dome tweeter and coupled chamber Diameter 25 mm / 0.98″ Power Handling (RMS/max.) 70 / 110 Watts Impedance 4 Ohms Efficiency 89 dB Frequency Response 2200 Hz – 24 kHz Membran Layout Coated silk Mounting Ø 48 mm / 0.19″ Mounting Depth 22 mm / 0.866″.