ST35 - Hertz 1.4" 100W RMS High Efficiency Compression Driver Bullet Tweeters CCAR (Copper Clad Aluminium Ribbon) voice coil | Extra-light aluminium membrane with high thermal dissipation | Anodized aluminium body, for maximum damping and vibration rejection. 44 mm (1.7 in.) voice coil | Ferrite magnet Power Handling: 100W Peak | Impedance: 4-Ohm Frequency Response: 2,5k  20k Hz | Sensitivity: 109 dB/SPL Magnet: Neodymium | Cone/Dome: Aluminium