It's important to maintain the face seal at all times, the thin pliant face seal creates a positive pressure environment within the helmet that is designed to keep surrounding pollutants at bay. If the face seal is damaged there is great risk that the pressure will be equal and contaminated air will get inside the helmet.
A face seal in good working order is essential at all times, replace at least every three months or earlier if unhygienic.
The Speedglas 9100FX air face seal is available in one size only, but one size fits all.
3M part number 534000
