HS-20RT delivers high sound pressure and precise control of the sound. It is not easily bent or broken as it is made up of very strong materials such as aluminum and by zinc die-casting. It is movable from 240° up-and-down and 160° left to right. It is designed to mount on the wall very easily. In addition, it perfectly operates under any climates as being accredited by EN-54-24(European Standard of audio announcements of loud speaker for fire alarm) with IP65 Class.