Die Cast Plastic Frame150 Watts RMS/300 Watts Max - Bolt hole dimension: F5mm (4×).4 Ohm Impedance - Diameter: F91mm.Frequency Response: 2.5 KHz-20 KHz - Mounting depth: 55.5mm.Sensitivity: 100 dB/w/m - Total depth: 61 mm.Number of bolt holes: 4 This die-cast titanium super tweeter will allow you to achieve the highest highs! This 1" aluminum driver contains a 1" titanium diaphragm for sweet, accurate highs. This 150 watt tweeter isn't lacking for power. Frequency response: 2.5 - 20 kHz. 4 ohm impedance.