WaterSentinel WS-21 Calcium Inhibitor Filter and Misting System Protector Polypropylene Made in US Quick, 1-step installation with the same OEM performances. Prolongs nozzle life by preventing scale buildup from clogging up. For use with all outdoor cooling systems. WaterSentinel brand ensures the highest standard. 102 Day warranty against manufacturer defects from date of sale with invoice from WaterSentinel. For Customer Service call 866-218-8473 Keeps your mist cooling system operating at peak performance Prolongs nozzle life by preventing scale buildup from clogging up Perfect for all outdoor mist cooling systems Simple instalation and use Proudly Manufactured in America with US based customer service