Kask Nirvana Helmet Elevate Your Training and Racing Aerodynamics is an important part of racing. With the ability to cut through the wind, you'll be able to achieve higher speeds with less effort. The Kask Nirvana Helmet provides unparalleled efficiency. It is engineered for the elite road rider, triathlete, and track cyclist. The Nirvana offers a remarkable 35% reduction in aerodynamic drag and a 19% increase in ventilation compared to the best aero helmets in its class. It also ensures optimal thermoregulation and enhanced endurance. The Nirvana features an eyewear port, Multipod 3D-printed internal padding that strengthens the helmet against linear and rotational impacts, and an Octofit+ helmet retention system that provides a finely tuned fit for enhanced safety and stability. Features Reflective graphics at the back enhances visibility in low-light conditions Aerodynamic design offers a 35% reduction in drag and a 19% increase in ventilation compared to other aero helmets Multipod 3D-printed internal padding strengthens the helmet against linear and rotational impacts SPECIFICATIONSCore Material3D-Printed Internal Padding Closure system Octofit+Safety Certifications CPSCIntended Use Road, Triathlon, Aero Weight N/ASizing Size Medium Large Head Circumference (cm)52 - 58cm59 - 62cm Head Circumference (in)20-1/2 - 22-7/8"23-3/8 - 24-1/2" | Kask | Nirvana Helmet Men's | Size Large In Black Matt