ALL SEASON - Pick the model that best fits your style and customize your helmet with our range of seasonal upgrades.BIKE LIGHT COMPATIBLE - The Asteroid and Meteoroid fit all new and older Bern helmets with a two-hole mount located in the rear of the shell. TEAM FIT - Non-adjustable die cut padding. THIN SHELL - Our tried-and-true technology, ThinShell, is the ultimate balance between hard ABS or polycarbonate shell thickness and interior EPS foam thickness. Safe, durable, and strong. Meets Safety Certification CPSC, EN1077B, EN1078 SIZE CHART: X-Small (52-54 cm), Small (54-55.5 cm), Medium (55.5-57 cm), Large (57-59 cm), X-Large (59-60.5 cm), XX-Large (60.5-62 cm)