EQUI-LITE Riding Helmet, by International Riding Helmets Sporty and lightweight. The Dial Fit System allows a custom fit with just one simple turn of the dial. 9 venting ports from maximum air circulation to keep you cool and comfortable. weighing 10 ounces, this versatile, fashionable helmet is a must-have. ASTM F1163.04a/USA/SEI Features Lightweight, weighing only 10oz! Front Ventilation 3-Point Harness Easy To Clean Outer Shell Dial Fit System to accommodate a pony tail Hugs the back of your head and reduces the tendency of your helmet to shift forward or backwards when you ride. Available in Small, Medium and Large. SMALL (6 1/2, 6 5/8, 6 3/4), MEDIUM (6 7/8, 7, 7 1/8), LARGE (7 1/4, 7 3/8, 7 1/2)