Use a soft ruler to pass the bulge above and behind the forehead around the head for a circle.
Victgoal Bike Helmet for Men Women with Led Light Detachable Magnetic Goggles Visor Mountain & Road Bicycle Helmets Adjustable Size Adult Cycling Helmets (Black Red, L: 22.4-24 inch (57-61 cm))
Victgoal Bike Helmet for Men Women with Led Light Detachable Magnetic Goggles Visor Mountain & Road Bicycle Helmets Adjustable Size Adult Cycling Helmets (Metal Blue, L: 22.4-24 inch (57-61 cm))
Victgoal Bike Helmet for Men Women with Led Light Detachable Magnetic Goggles Visor Mountain & Road Bicycle Helmets Adjustable Size Adult Cycling Helmets (Black White, L: 22.4-24 inch (57-61 cm))
Victgoal Bike Helmet for Men Women with Led Light Detachable Magnetic Goggles Visor Mountain & Road Bicycle Helmets Adjustable Size Adult Cycling Helmets (M: 21.3-22.8 inch (54-58 cm), Black Red)
Victgoal Bike Helmet for Men Women with Led Light Detachable Magnetic Goggles Visor Mountain & Road Bicycle Helmets Adjustable Size Adult Cycling Helmets (Black Red, XL: 23.2-24.8 inch (59-63 cm))
Victgoal Bike Helmet for Men Women with Led Light Detachable Magnetic Goggles Visor Mountain & Road Bicycle Helmets Adjustable Size Adult Cycling Helmets (Black White, XL: 23.2-24.8 inch (59-63 cm))
