The TSG "Superlight Graphic Design" BMX Helmet - Deep Sea is a very light and high quality helmet which is very comfortable to wear. It has some ventilation holes for air floating.

Size chart (head circumference, about 1cm over eyebrows):

L/XL: 57-59cm
Material: Polycarbonate, EPS, Polyester, Nylon
Cover: ultralight polycarbonate
Core: lightweight EPS impact-foam
Safety Standard: CE EN 1078, CPSC