Premium features certified protection road-worthy styling & our exclusive Hair Port SX fit system tailor-made for a ponytail make the Duet a great value for any female cyclist.> One-size system based on women’s head sizing designed for easy & accurate fit> Hair Port SX fit system is ponytail compatible & features micro-adjustable dial for easy secure & accurate fit> 4th Dimension Cooling System optimises ventilation> Tri-Fix web splitter for enhanced comfort & ease of strap adjustments> In-moulded shell improves strength & reduces weight> Reflective webbing & decals for added night time visibility> Patented clip-on visor included> Complies with one or more of the following safety standards for bicycle helmets: CPSC SNELL B90A CE & AS/NZS