Pyle-Pro PDS382 1.75'' Titanium Screw On Horn Driver 8 Ohm 1-3/8'' x 18 TPI Midrange/Tweeter Compression Horn Driver - Sensitivity: 104dB @ 1W/1M Titanium Diaphragm - 8 Ohm Impedance 1.75'' (44.4mm) Flat Aluminum Voice Coil - 200 Watts RMS/400 Watts Peak 21 oz Magnet Structure - Terminals 205 Type Frequency Response:1000Hz-20KHz - Fits Horns with 1 3/8'' x 18 TPI Threads