Whether learning how to ride on their balance bike or already a pro on two wheels, the Bell Youth Lil Ripper Bike Helmet offers fun designs and a safe, comfortable fit. It has 10 vents to keep them cool and a SmartLock(TM) No-Pinch Side Buckle. FEATURES: Great for beginner riders Action Fit(TM) system provides an adjustable, secure fit with the turn of a dial Ventilation: 10 vents Fusion in-mold polycarbonate shell with EPS foam liner provides strength and greater durability SmartLock(TM) No-Pinch Side Buckle for a comfortable, quick fit Complies with U.S. CPSC Safety Standard for Bicycle Helmets for persons age 1 and older (Extended Head Protection) SIZING: Toddler: 45 - 51cm Child: 47 - 54cm