Description The A-523 provides a low cost, accurate, reliable and aesthetically appealing means to sense pressure in rooms, laboratories, hospital operating theaters, clean rooms or any other application in which the area is under positive or negative pressure. The A-523 is designed to interface with the MAMAC PR-274 & PR-275 low pressure sensors to provide a low cost labor saving alternative to expensive field derived solutions. Rugged UL-94-V-0 rated white ABS plastic with color matched mounting screws, brass union and soft wall tubing is provided as a kit for ease of field installation. Designed to be flush mounted or on a 2" X 4" standard electrical junction box.