Jockey skull cap suitable, for instance, for cross-country riding during horse trials. With front and rear ventilation slots. Includes a mesh liner designed for maximum ventilation. The skull cap has a low profile, while interwoven silver ions provide built-in anti-microbial protection against odours and microbes. Revolutionary GRpx® technology creates an unrivalled fit using scientifically designed grippers. For riders who have trouble keeping their helmets firmly in place, the GRpx harness on the PRO II and AYR8 helmets can be the answer. The integrated grips on the harness fit tightly against the base of the skull for exceptional stability. Lining is easily removable and washable. The shell is available in three sizes: S, M, L. Liner available in sizes 52-65. The replaceable liner makes this helmet ideal for growing children, as you can gradually adjust its size by replacing the liner with a different sized one. Shell S: Size 52-55. Shell M: Size 56-59: Shell L: Size 60-65. Example: If you buy a helmet in size 56, the size of the shell is Medium and the size of the liner is 56. Then you have the option of buying an inner lining/liner in sizes 57, 58 and 59. Approved according to Kitemark PAS015:2011 and certified according to SEI ASTM F1163.