Fangrui Product Details 1. With The Blue Caps In Place Wash The Exterior Of Each Fluoride Filter Elements 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 The Priming Button Creates A Seal Between The Faucet And The Fluoride Filter. Place Your Thumb On Top Of The Faucet To Apply Pressure, To Create A Better Seal (as Seen In Picture). 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 30 Seconds Or Until Water Runs Clear. 4. Turn The Fluoride Filter Over And Prime The Opposite End (reversing The Flow Of Water) Repeating Steps 3-5 Until Water Runs Clear From Both Directions. 5. To Determine If The