AVAILABLE SIZES: For the perfect fit, measure the circumference of the head starting from the middle of the forehead to ensure you choose the correct size. S- suitable for 48-54cm, recommended age 3-8 years old; M- suitable for 55-57cm, recommended age 9-13 years old. SHOCK RESISTANT: This kids skate helmet features a shock absorption and impact resistant system. The ABS outer shell with EPS foam padding can absorb external pressures help absorb impact and protect the head during impact. With CE certification, this helmet offers excellent protection for outdoor sports like skateboarding and cycling. BREATHABLE DESIGN: The ventilation system with 11 ventilation openings ensures sufficient fresh air. The skate helmet reduces sweat and keeps you cool even during intense activities. PRECISE FIT: The children's helmet equipped with adjustable straps and a buckle allows children to adjust flexibly to achieve a better fit. It can be flexible to different sizes for children and can be adjusted to the growing child. WIDE RANGE OF USE: Essential equipment to protect your child from injury. This skate helmet can be used in many outdoor activities, such as rollerblading, inline skating, scootering, cycling, rollerblading, skiing, etc.