Helps prevent premature disposal of the mask and during wear the cloth strap feels comfortable and cool. Exclusive Ventex[R] valve lets the hot air out faster so breathing resistance is reduced and workers stay cooler. Softspun[R] lining for increased comfort and durability. Dura-Mesh[R] shell protects the filter media so it stays cleaner looking longer. The shell also resists collapsing in hot, humid environments so the respirator holds its shape longer.