ACT multi shell in-mold construction with overlapping Polycarbonate shells creates the lightest and strongest helmet possible. The Level 3 venting system actively removes heat and moisture without uncomfortable direct airflow to your head. All the external vents are offset from the internal vets which you can completely control though the open/close system on the top of the helmet. Pret's Ripcord System (RCS) gives you a micro adjustable fit so you can dial in the right size.