Air-Lite DFS Helmet by International Riding Helmets (IRH) Dial-Fit system, replaceable Softec Padding, nylon harness with quick release buckle, and scratch-guard bottom trim. Sizing: S (fits hat sizes 6 1/2 - 6 3/4) M (fits hat sizes 6 7/8 - 7 1/8) L (fits hat sizes 7 1/4 - 7 1/2)