Valve Deactivator for UK Cambridge Mask Face Basic N95 and PRO N99How do I attach my Valve Deactivator? First turn the mask fully inside out. Then peel the large, orange Valve Deactivator off the wax paper and stick over the valve on the inside of your mask. Apply gentle pressure to ensure it has adhered correctly to the valve, but take care not to tear it or break your valve. Position the informational valve deactivated sticker on the outside of the valve where it is visible to others and stick it down securely.