[Full Protection with DOT]: AHR RUN-F3 full-face helmet, meeting DOT safety standard, provides injury prevention by fully covering your face & head and perfectly fits most people's head by its [Safety & Comfort]: High-density EPS foam protects head by absorbing impact and enhancing cushioning; ABS Shell for great resistance to impact and long lifespan; Liner with comfortable, skin-friendly [Great Ventilation & Streamlined Design]: External air ventilation system including front, back & chin vents brings light and fresh flow of air for providing coolness & comfort when riding; [Shield & Quick Release Buckle]: Transparent shield brings clear & wide vision and strong protection from impact or wind, and is easy to pull up or down as your like or take off for cleaning or [Simple to Clean]: Removable side cheek pads & washable head liner for easy & regular cleaning and keeping hygiene; M size helmet perfectly fits most people whose head circumstance ranges from 22