Check the listing for details. Waterdrop 200-Gallon Long-Life Elfin 5-Cup Water Filter Pitcher with 4 Filter. Condition: New. Listed at 44.99 USD. Product DescriptionCertificate C0145653, by NSF International, 2021.Step 1: Soak The Filter to Activate ItAfter taking out the filter, please soak it into cold tap water for 10 mins to activate it.Step 2: Clean The PitcherWash a pitcher, a lid and a reservoir with a mild detergent and flush them thoroughly with water. DO NOT wash them with a dishwasher or an abrasive cleanser.Step 3: Install and CleanFirmly press the filter into the reservoir to form a tight seal; discard the first two pitchers of filtered water or use it to water plants.Step 4: Activate The Filter Life IndicatorHold the button for 5 seconds until the blue light flashes to activate the indicator. Monitor the filter status as you pour water out. Note: Remember to execute this step every time when the filter needs replacing.