ides D-Bike Kids Helmet S - Pink Target Head Circumference: 53-56cm Age Guide: 4-8 years old Size: W220 x L260 x H160mm Perfect for bicycles, kickboards, skateboards, etc. A must-have item when riding! This sturdy helmet uses a hard shell. The dial adjuster allows for easy size adjustment to fit your child's head circumference. Also, the 3D pads inside the helmet can be adjusted to accommodate your child's growth. The helmet can be easily put on and taken off with one touch. Will be shipped in a substitute box. Non-smoking, no pets. Thank you very much.