Autofit system, In-mould (1-piece) construction, 16 cooling vents. Autofit system is an automatic fit system that delivers equal and constant tension by eliminating the need to manually adjust helmet retention: simply pull the helmet on, and the front and rear baskets of the helmet will adjust themselves to provide a great fit. 16 air vents. Head size from 50 to 55cm. Foam padding. Quick-release buckle fastening. Manufacturers 2 year guarantee.