The original OEM for the ULTRAWF water filter model is the PureSource Ultra Filter by Frigidaire. The PureSource Ultra filter purifies your water supply by using advanced filtration technologies, which creates clearer ice and cleaner, better tasting water. So what exactly does this filter protect your home from? Public health and environmental organization NSF/ANSI International deemed the Frigidaire filter fit to handle some of the most potentially harmful contaminants found in water. Such contaminants your water is safe from with this OEM filter include lead, atrazine, lindane, cysts, chlorine, and giardia. Due to its filtering performance, the NSF/ANSI certified the Frigidaire filter for meeting both international Standard 42 and Standard 53. It should be noted that this water filter should be changed at least once every six months for optimum filtration performance.