How to use?
- Put the mask on your face.
- Fasten by VELCRO.
- Adjust the nose clip to a most comfortable position.
- Breath test. Put your hands on the both side, and then breath to test whether air leaks. If yes, tighten the Velcro and try again until no air leaks.
How to change filter?
- Demount the two valves counterclockwise.
- Replace the old filter.
- Mount the two valves clockwise.