Aqua Sentry Retrofit Filter Kit for unfiltered Elkay drinking solution products (Coolers + Fountains). Filter should be replaced every 500 gallons or 6 months after installation. Equipped with Quick-Disconnect fittings on each end of the in-line filter. Designed to reduce cysts such as cryptrosporidium and giardia, lead, particles and chlorine. Also reduces odors and discoloration from incoming water. Filter is certified to NSF 42 and 53 for cyst, lead, atrazine, lindane, particulate class 1, chlorine, taste and odor reduction.