Helmet bicycle spokey ninja 53-55 cm 943425 & nbsp; helmet spokey is for os & oacute; b adults and adolescents. Provides safety during ride on bike, bmx, rollers or other other activities sports. Their material & oacute; v. System Head Lock, i.e. internal knob will allow na fit to circumference head. Internal foam EPS absorbs force shock shock during fall and cushioning shocks vibrations resulting from driving after M substrates. Holes ventilation. Technology Out Mold in Practice means that outer outer and internal not are with themselves permanent connected. C Possible shocks. & nbsp; data technical: & middot; system adjustment: head lock & middot; regulation circumference: 53-55 cm & Middot; Norma: 1078 A1: 2013-04 & Middot; Coating Outdoor: ABS, Out Mold & Middot; Internal layer: EPS & nbsp; & nbsp;