【Comfort Fit】:Adjustable 6-point suspension system for improved shock absorption and overall comfort.The replaceable soft egyptian cotton core sweatband with porous coating for maximum sweat absorption make workers comfort fit during whole working hours.Comfortable and convenient chinstrap with molded chin-cup for extra security and stability.Also it's easy to remove. One adjustable size fits most. Helmet size range from 53-63cm/ 20.86-24.80 inch. 【More Humanized Design】:Sliding vent holes allow easy opening and closing based on weather conditions .Complete with Rapid-Dial ratcheting headgear,One-handed adjustment design allows workers to modify fit without removing work helmet,even with gloves on. 【Extra Protection】:Accessory slots allow the use of multiple hard hat accessories.And the safety helmet has Hi-Viz design on the front-rear-and sides of the helmet to allow the user increased visibility under low light conditions. 【Ideal For】:GREEN DEVIL Mervex Vent safety helmet is suitable for construction,tree climbing work,woodworking,mechanics, forestry,manufacturing,height and scaffolding work ,in any trade that requiring general head protection. 【Reliable&Stylish New Generation Safety Hard Hat】:GREEN DEVIL safety hard hat is made of high impact penetration resistant ABS materials, lightweight, strong and comfortable.A good choice to protect heads against falling objects, impacts, bumps, and scrapes.And these safety hard hats meet ANSI Z89.1-2014 Type I Class C standards, also approved by CE(EN397:2012 -20℃). Give you and your company the ideal choice in ANSI Type I head protection. 1