Snell Memorial Foundation. The most trusted, oldest, and prestigious testing laboratories in the world for all types of crash helmets. They are a private, non profit company. They are the only laboratory which has a continuous testing program after the helmet is certified to their standards. Look inside a helmet.
Some small kids have large heads and some large people wear small or medium.
Available about May 2001. This is a murky area. One crash and its sayonara for the helmet. Our skateboard, inline skate, and scooter helmets are of a different design and construction. The outer shell is ABS plastic like football and hockey helmets.