Dayton Audio DT250P-8 1" Polyimide Compression Horn Driver 1-3/8"-18 TPI 8 Ohm Wide 1,000-20,000 Hz frequency response Optimized throat design and phase plug Polyimide diaphragm for smooth, detailed reproduction Versatile 1-3/8&quot;-18 TPI mounting fits a wide variety of horns High sensitivity and power handling