The Airhole is standard on all of AIRHOLE's masks and is designed to allow breath to escape freely, avoiding the build up of condensation to keep you dry, warm and goggles fog free. Microfleece is a traditional lightweight, soft fabric that stays warm, even when wet. Because it doesn't retain water, Microfleece will keep your face warm and cozy in varied conditions. They also apply a DWR (Durable Water Repellent) coating to bead water as an additional defense against the elements to keep your face dry and comfortable.