Bell Trigger Youth Bike Helmet Sturdy helmet constructed of an EPS foam layer bonded with a microshell Adjustable ErgoDial fit system provides a snug and comfortable fit Straps around the ears are easy to adjust with locking levers Pinchguard buckle specifically designed to prevent kids from pinching their chins Universal youth size fits 19.75 to 22.5-inches (50 to 57-centimeters)