Available in L (580 millimeters) size. Outer shell injected from special high impact grade of engineering thermoplastic. Multi-position articulating optically true injected polycarbonate visor duly silicon hard coated for scratch resistance properties. Quick release chinstrap mechanism for ease of operation and safety. New helmets may feel tight at first. This is normal and required to ensure safety. Foam requires around 10 days to adjust to rider's head shape. Studds Marshall Half Helmet (Matt Blue , L).