Klein hard hats are made of high-density polyethylene for durability. Unique nape straps hold the hats firmly in place and they are washable and shrink- and stretch-proof. The porous brow pad promotes ventilation for comfort. Klein hard hats are a standard size that fits head sizes 6 – 8. And they have a full 6-point ratcheting suspension. They meet ANSI Z89.1–2003 specifications for Class E.