This is Stihl's Advance X-Vent helmet system. It comes with a comfortable six point harness and ratcheted wheel mechanism that allows for easy size adjustment while wearing. Has a NRR 25 hearing protection and an etched spring steel mesh visor. The ADVANCE X-VENT (Type 1, Class E) has a non-vented helmet with a 20,000 V electrical rating. CSA & ANSI approved.