Borrowing from utility, this modern cap is made from recycled nylon with breathable mesh panels on either side. It's designed with a drawstring toggle for a personalized fit.  Toggle closureRecycled polyamide is polyamide made from textile waste in production Shell: 100% Recycled polyamide (Recycled nylon). Details and lining: 100% Recycled polyester. Excluding trims Inner circumference of size XS/S is 22.44”, M/L is 23.23”