The Atlas Sound PD-30 is a 30W 8 Ohm compression driver that is weather resistant so it can be used indoors and even outdoors. It features a 1.5" voice coil and a plane wave frequency response of 300 - 3,900 Hz making it ideal for expansive and/or high-ambient sound-level areas. It is terminated in standard 1-3/8"-18" thread male couplings for use with screw-on horns, or with Atlas Sound Model DA-FH adapter for bolt-on type horns.