509 F01003800-110-302 - Hand lay-up carbon fiber composite construction. Upper vents with on/off shutter closure for airflow control. Weight: DOT, FMVSS 218/ECE 1150 grams. XS to 4X sizes available in three shells for optimal fit and minimal weight. Fidlock chinstrap strap closure for easy in and out. Go-Pro mounting capability, improved design. Perfect fit between helmet eyeport and 509 goggles. 509 helmet bag included. Pro-Series Breathbox for complete protection, removable for optimal air flow. Reinvented to ride even harder, the second generation of the bestselling 509 Altitude series unleashes a whole new animal. Leading the charge is the 509 Altitude 2.0 Carbon.