Pyle-Pro PDS111 1'' Neodymium/Titanium Screw On  Horn Driver 8 Ohm 1-3/8'' x 18 TPI Midrange/Tweeter Compression Horn Driver - Sensitivity:99db 1W/1M Neodymium Magnet /Titanium Diaphragm - 8 Ohm Impedance 1'' (44.4mm) Flat Aluminum Voice Coil - 100 Watts RMS/200 Watts Peak 21 oz Magnet Structure - Terminals 205 Type Frequency Response:2000Hz-20KHz - Fits Horns with 1 3/8'' x 18 TPI Threads