Mountain bike helmet suitable for men sizes 54 58 cm 58 62 cm us sizes sm ml surface matt number of air vents 22 applications all mountain enduro chin padding with chin pad visor with visor adjustable screw assembly size adjustments wheel adjustment system headring features neck protection construction double in mold weight 320 g inner material polystyrene eps helmet technology ixs ergofit ultra marks of approval cpsc en din 1078