Giro Roc Loc 4
The Roc Loc is Giro's patented helmet fit and stabilizing system. The Roc Loc hugs the back of your head and reduces the tendency of your helmet to shift forwards or backwards. Unlike most systems, the Roc Loc design provides adjustable tension that is independent of the helmet straps. What this means is that you don't have to over-tighten the straps to get a snug, comfortable fit.