Leatt MTB Enduro 4.0 Men Full Face Helmet Stealth S 51-55cmDH certified lightweight Polymer shell Removable chin bar with easy fit attachment system Sunglasses dock port for easy, secure storage Fidlock magnetic closure system 360 Turbine Technology Reduced peak brain acceleration by up to 30% at impact speeds associated with concussion Reduces peak brain rotational acceleration by up to 40% Maximized ventilation with 18 vents. Optimized for riding and effective even at low speeds Moisture wicking,