Affordable, durable horns for demanding sound reinforcement applications. The re-entrant style horn flare design provides an expansion path that is longer than conventional straight horns; this ensures that the lowest possible frequency response can be achieved. The Dayton Audio RPH20 PA horns are formed from lightweight aluminum and painted with a durable polyester finish, so you know that they will survive years of exposure to sun and rain. Great for indoor or outdoor applications, sturdy mounting yoke for precise alignment included. Standard 1-3/8"-18 threaded throat; 20" mouth diameter, 13" depth.