Spin Action Fit, offers maximum adjustment 21 vents Side-squeeze buckle offers easy adjustment Women's fits head size 52-58cm CPSC 1203 Bike compliant Designed for the road, or the road less traveled, the Bell Cadence is the ideal choice for road rides and joy rides alike. Its compact profile and 21 large vents keep you cool as you cruise, while the easy one-handed adjustable Spin Action Fit system gives you unbeatable comfort. No matter how fast or how far, the Bell Cadence is the perfect partner for your ride.