The Macon EPS 14/15 Helmet from Bern Standards: ABS Shell with EPS Thinshell Sizing:S/M: 54-57cm, M/L: 55.5-59cm, L/XL: 57-60.5cm Liner:EPS The Macon dishes up core clean lines that will look good during any season. Dishing out comfort & safety the Macon has a few different constructions that are sure to meet your needs whether youre on your board, bike, the slopes. The EPS/ Thin Shell model is a certified helmet for both bike & snow. This model uses a thin ABS shell lined with EPS Foam to create a burly lightweight lid. A certified helmet is designed to crack & absorb a gnarly impact, much like you may encounter should you take a hard spill on the hill or riding your bike. Depending on the season your helmet will come with either an EPS Summer Comfort Liner or an EPS Winter Liner & you can buy the alternating seasons liner based on your needs to keep up with you through the seasons.