Atlas Sound DR Series double re-entrant horns are designed for use with compression driver units to offer superior music and voice communications over distance and ambient noise. The circular projectors are equipped with a resonance damping ring for best response through an extended frequency range. Weather-resistant units will accommodate Atlas Sound PD and SD Series compression drivers or any driver with standard 1 3/8" -18 male thread coupling. The integral "U-type" steel mounting bracket provides maximum directional aiming flexibility and enhances installation capability when used outdoors or in industrial environments. The rugged all-metal, exponentially-flared horns are finished in durable grey epoxy.