From the seller

HIGH RESISTANT MATERIAL : Special material impact resistance: This Bicycle / bike helmet uses high-density, durable and tough pvc and eps foam. The Integrated molding with superior technology is helpful to decrease the impact force and protects the rider's head during crash ADJUSTABLE SIZE : FABSPORTS bike helmet comes with a dual fit adjustable design, there is a adjusting knob at the back of the bike helmet that helps to adjust the head circumference (size: 22.44-24.41inch/(57- 62cm)) and it also has side strap to make the helmet fit most cycle riding men and women SUPERIOR VENTILATION: The integrated flow vents help to keep cyclists cool and it is also helpful to increase the speed. The inner sponge lining can be removed to wash. REMOVABLE INNER LINING - The inner lining is detachable and is also washable. Not only it protects your head but also keeps it hygienic as you can wash the same. MULTIPLE SPORTS USE : This helmet can be used for multiple sports like for Road cycling, Mountain Biking, Skating, for Skate Boarding and many other uses.