Rollsys retention system * Rigidity Brace System (RBS) adds reinforcement in the event of multiple impacts * In-Mold (2 piece) construction and 24 vents * Available in two size options: Unisize for 53-61cm heads and and oversized (XL/XXL) for 61-64cm heads; check list of attributes below for size range in centimeters * Internal ventilation channels for optimum airflow and Coolmax padding