These MSA hard hats are the number one hard hat for most industrial applications. The shell is made with a durable injection-molded, high-density polyethylene. These MSA hardhats come with either the Staz-OnTM (pin-lock) suspension or the Fas-TracTM (ratchet) suspension for superior head protection. In addition, this MSA cap is designed with an accessories slot to accommodate many add-on features