V-Gard , Yellow, Ratchet Suspension Non-Slotted Protective Hat, Made Of A Durable Polyethylene Shell & A Fas-Trac Suspension System That Adjusts Snugly For A Comfortable Fit By Simply Rotating An Adjustment Dial In The Back Of The Hat, Meets Or Exceeds The Application Requirements For A Type I Helmet, As Outlined In ANSI Z89.1 1997, Class E & G, The Suspension System Is Adjustable To Fit Hat Sizes From 6-1/2 To 8.