Octal Aero is based on the award winning Octal helmet, but has been developed further for aerodynamic performance and to be used in time trial and events where low drag is crucial, without sacrificing safety, weight or comfort. It provides more coverage and additional protection of the temples and back of the head. To further improve safety, the EPS liner is strategically thicker in most exposed areas and is covered by the outer PC shell. The unique and fully wrapping unibody shell construction functions as a monocoque and enhances the safety properties and construction integrity of the helmet while maintaining a low weight. The ultralight size adjustment system ensures a comfortable and secure fit and the internal Coolbest padding helps reduce the temperature in the interface between the helmet and your head. TECHNICAL FEATURES External microshell for aerodynamic performance High performance EPS liner, optimized in density Fully wrapping unibody shell construction Ultralight size adjustment system, designed with low contact area Straps molded into liner Temperature regulating Coolbest padding Color finish: Navy Black: matte; other colors: shiny CERTIFICATIONS EN 1078, CPSC 12.03, AS/NZS2063-2008 SIZES & WEIGHT EN 1078 Small: 50-56 cm (210 g) Medium: 54-60 cm (215 g) Large: 56-62 cm (225 g) SIZES & WEIGHT CPSC 12.03 Small: 50-56 cm (260 g) Medium: 54-60 cm (285 g) Large: 56-62 cm (325 g)