Model 9929-LH Rack-Mount Alarm System:
Has the capabilities and options of Model 9928 plus three DPDT relays
5-1/4" x 19" (standard EIA dimensions) device designed for mounting into rack cabinet or panel. It has all of capabilities and options of the Model 9928. In addition, it has three DPDT relays (one for each type of alarm condition), rated 10 amps, resistive. These relays may be used to activate ventilation fans, sirens, or other equipment.