1. With the blue caps in place, wash the exterior of each fluoride filter element with water and mild dishwashing soap, then rinse. With clean hands, remove both blue caps from each end of both filter elements. 2. Place the rubber priming button (tan colored) onto one end of a fluoride filter and align the hole of the filter with the hole of the rubber washer. Press the priming button up against the sink faucet so that it creates a seal between the faucet and the fluoride filter. Place your thumb on top of the faucet to apply pressure and create a better seal (as shown in the image). 3. While holding the priming button against the faucet, turn on the cold water slowly, allowing water to fill the cavity of the filter and flow from the opposite end. Allow water to flow for at least 2 minutes or until water runs clear. 4. Turn the fluoride filter over and prime the opposite end (reversing the flow of water), repeating step 3 until water runs clear from both directions. 5. To determine if the filter is fully primed, collect the filtered water in a clear glass and hold it up to the light to check if all cloudiness is gone. If not, continue priming until the water is clear. This filter is now primed and ready to install. Repeat priming steps 1–5 for each additional fluoride filter. Material: Plastic Color: White Package Contents: 4 x Water Filter Note: Due to different product batches, the appearance of components may vary slightly, but this does not affect functionality. The package includes only the items listed above. Other products are not included. Light reflection and differences in display screens may cause slight variations in color between the image and the actual item. Measurement may vary by +/- 1–3 cm.