The Aeroshell snaps into place and protects the riders head from wind and rain while still allowing for some air movement under the front of the helmet and out the rear vents. The Aeroshell is unique in that it is easily removed from the helmet when riding conditions are such that additional ventilation is desired. Snap it on when the rain is pouring down and pull it off when the sun starts to shine, the Aeroshell is the perfect tool for every possible condition.
Additionally the Aeroshell provides a significant increase in Aerodynamic performance once it is installed on the helmet. By closing off the ventilation holes, the amount of aerodynamic drag the helmet creates is strongly reduced, making your road helmet into an aero helmet and resulting in a faster ride.