With exceptional cooling & comfort features certified protection road-worthy styling & our exclusive Hair Port SX fit system thats tailor-made for a ponytail the Duet confirms itself as a tremendous value for any female cyclist.> One-size system based on women’s head sizing designed for easy & accurate fit.> Ponytail-ready Hair Port SX fit system with micro-adjustable dial for an easy accurate fit.> 4th Dimension Cooling System optimizes ventilation.> In-moulded shell improves strength & reduces weight.> Tri-Fix web splitter for enhanced comfort & ease of strap adjustments.> Reflective webbing & decals for increased visibility in low-light conditions.> Patented clip-on visor included.