Dwyer BDPA-05-2-N is an adjustable differential pressure alarm with an enclosure rating of IP21. It can be powered by 16 to 30 VDC, 18 to 30 VAC, or a user-replaceable 3.6 V LS14250 lithium metal battery. The alarm is suitable for air and noncombustible compatible gases and can handle process and ambient temperatures from -4 to 185°F (-20 to 85°C). It has a switch type of SPDT and a maximum operating pressure of 40" w.c. (10 kPa). The alarm is equipped with a red LED and audible alarm for indication, and its battery acts as a back-up in case of power loss. This alarm has a battery life of approximately 1.5 years with a 3.6 V/1.2 Ah battery and features an alarm acknowledge button. Its compact design allows for vertical mounting with pressure connections pointing downwards.