Material (MATERIAL): Imported PC shell EPS imported inside Product packaging: 30.5x22.5x18CM Technology (TECHNOLOGY): One-piece molding (In-Mold) COLOR: 13 colors are available Ventilation holes (VENTS): 16 Size (SIZE): 46-53CM Inner width (WIDTH): 16CM, inner length: 20CM Construction: External IN-MOLD (integrated molding) anti-impact PC, internal EPS integrated molding For: children's balance bike, scooters, scooters, bicycles, skating and other outdoor sports! Specifications: 1.Large 16-hole open vents improve airflow and reduce weight, and have excellent breathability 2.Anchored Y-belt anchoring system provides better fit 3.Helmet all-mountain helmet coverage rate is low to increase protection, multi-density impact reduction system provides excellent protection 4.High-quality lining and chin padding for added comfort 5.Single-drive hand plate fixing system provides easy adjustment 6.Removable sun visor and an additional replacement inner pad