Lazer Elle Helmet Includes matching cycling cap Features 22 vents for airflow In-mold construction offers lightweight protection Advanced Rollsys retention system has adjustable height Rollsys basket Rigidity brace system for multiple impact protectionLight straps with straight strap dividers (SST) ensure that straps lay flat against the headPonytail compatibleSmall Fits: 52-56cmMedium Fits: 55-59cmLarge fits 58-61cm