My twins used this helmet from one and a half to three and a half years old. I think it's more solidly built than other helmets. The belt adjustment and the movement of the hook are also fine. tokyobike's mint green and white children's helmet, with ventilation holes, combines safety and comfort. Retail price: 7810 yen - Widely compatible from 47cm to 52cm. - Size adjustment dial is easy for children to turn themselves. - The buckle has a cloth to prevent pinching cheeks. - Cute ventilation holes that look like flower patterns from above. - Designed with the image of a nursery school hat, it has a simple shape that matches any outfit. - The cushion part that touches the forehead can be removed and washed for hygiene.