<p>Easy to install the mask Filter:</p> <p>1. Open the mask to expose the interior of the filter valve.</p> <p>2. According to the OPEN directions on the valve, turn the valve counter(clockwise), to separate the valve.</p> <p>3. Remove the filter.</p> <p>4. Replace the new filter, reverse the above steps, clockwise rotation of the valve, over.</p> <p> </p> <p>Packaging includes: 1x Cycling m.a.s.k,5x Activated carbon filters.</p>