CS-51 Cuno Inline FilterThe 3M Cuno CS 51 Water Filter is designed for use primarily in vending systems and commercial drink machines, but is compatible with any system that uses the CS 52 or CS 451 water filters. The CS 51 filter reduces chlorine and scale to provide clearer, better tasting water for up to 1500 gallons of use. Does your filtered water have a poor taste or odor? It's time to change out your old filter cartridge for a new one.