Foam padding is used to reduce wind flow, prevent debris from getting into your eyes and reduce vibration. There are three types of foam padding: open cell, closed cell and neoprene.
Open Cell Foam tends to be lighter, softer and more sweat absorbent than closed cell foam. Open cell foam also can provide a better seal or fit because its softer and conforms to the contours of the face better.
Closed Cell Foam has low water absorption making it more weather and chemical resistant. It also provides some ventilation to reduce fogging and can be more durable than open cell foam.
Neoprene Foam is a flexible and durable sponge rubber that provides good thermal and moisture insulation and form fitting which is able to resist ozone, sunlight, oxidation, many petroleum derivative and chemicals.