The WFDN Series Waterflow Detector fromSystem Sensoris redesigned to meet the needs of today’s fire sprinkler professional. The new features of the timer dial, cover, and terminal block add convenience and save on installation time. The new timer dial is a first for waterflow detectors with a built-in time delay. It is large and easy to turn, but its high-contrast pad-printed markings and tactile features make it easy to set by feel in dimly lit or hard-to-reach locations.