Mini Dial fit system and a side-squeeze buckle for simple adjustments Reflective coating for additional visibility Visor shades your eyes from the sun Fits head sizes 54 - 61 cm CPSC 1203 Bike Compliant Gear up for your next bike ride with the Bell Adults' Cadence Bicycle Helmet. Use the Mini Dial fit system to achieve the proper sizing each time, and shield your eyes from the sun with the visor. Reflective paint helps increase visibility so you can feel more comfortable riding day or night. Whether you're taking a ride down the trail or heading around town, this ventilated helmet will keep your head cool and protected.