Adjustable: Helmet Side Release Buckles Adjust and Fasten Quickly, Fits for 21.65-24.41inch/55-62CM Head Circumference. Recommend: Men, Women, a Good Choice for Outdoor Sports. Multifunction Helmet: Suitable for , Cycling, Climbing, Riding, Camping, Skiing. Protective : Helmet Can Better Shield Your Head from Sunshine and Rain. Lightweight: Lightweight Helmet Will Not Cause Burden to the Your Head During Cycling. Size:11.02*5.12inch/28*13cm.