- Single or double door use - Wall or ceiling mountable - Internal vertical pointability - Wrap-around coverage pattern - Selectable relay trigger mode The DS150i Series consists of the DS150i Detector (light gray) and the DS151i Detector (black). They are specifically designed for Request-to-exit (REX) applications. The DS150i and DS151i detect motion in their coverage area and signal an access control system or door control device.