Water flow detector designed to detect fire sprinkler activations and send an alarm to a fire alarm panel and/or local fire authorities when water flows through fire system piping. Waterflow detector is designed for indoor and outdoor use in commercial, residential and industrial water-based systems. It reduces the number of false alarms caused by pressure surges or trapped air. UL listed, FM listed, and nationally recognized safety standards. Available in a variety of diameters starting from 2" up to 6".