Product description, features & benefits:
The Macon 2.0 is Bern’s skate inspired hard-shell lid, featuring the durability you need for All Season adventure. A whopping 20% lighter than the original, the Macon 2.0 delivers optimal style in a helmet that’s lighter, more comfortable, and more dependable than those wallet-crushing options.
Features:
All Season  
Pick the model that best fits your style and customize your helmet with our range of seasonal upgrades. 
- Winter & Summer Knits Included
 - Compression Molded Padding
 - Lay-Flat Adjustable Straps
 - Available in Small, Medium, or Large (see below for specific dimensions)
 - Available in Matte Black finish
 
Safety Standards:
- Complies with U.S. CPSC Safety Standard for Bicycle Helmets for Persons Age 5 and Older
 - EN1077B
 - EN1078
 - Construction ThinShell
 - Fit System Compass Fit
 - Vents 12
 
Sizing Chart
Small: 6 1/2 - 7 Hat Size, or 52 - 55.5 centimeters
Medium : 7 - 7 3/8 Hat Size, or 55.5 - 59 centimeters
Large: 7 3/8 - 7 7/8 Hat Size, or 59 - 62 centimeters 
How do I measure my head size?
Using a cloth tape measurer or a piece of string, measure around your head just above your eyebrows and ears. The measurement obtained is your normal helmet size. You may wish to select a slightly larger or smaller size depending on your personal preference (e.g. if you prefer a tighter fit, select one size smaller). Helmet linings do compress, so if your helmet is slightly tight, it will loosen up a bit.
For more information, click on the following link: 
https://www.youtube.com/watch?v=OYCsbWYNIU4