Giro Aries Spherical Roc Loc 5 Air+ Fit System Large BlackThe Giro Aries Spherical Roc Loc 5 Air+ Fit System brings together performance and simplicity. With a single dial you can adjust the angle and tension of the helmet. The design raises the helmet increasing the performance of the vents built into the helmet and increasing the surface area of cool air rushing over you as you ride. Only compatible with Giro Aries Spherical Helmets.196178160797