Reinvented to ride even harder, the second generation of the bestselling 509 Altitude series unleashes a whole new animal. For those who run at redline, the new 509 Altitude 2.0 Carbon Fiber 3K Hi-Flow Helmet maximizes airflow with open upper and rear vents plus a 40% larger chinbar intake. Everything else is what you’d expect from one of the world’s bestsellers, including a new hand lay-up carbon composite construction that makes this helmet lighter, stronger, and even more comfortable. DOT approved. Meets the FMVSS 218 Standard