Compatible with Alpinestars RACE Tech-airbag onlySize Guide4042444648505254EURO SIZE5052545658606264LETTER SIZESMLXL2XL3XL4XL5XL Optional Armour Size Guide (see related items):Protector typeJacket sizeProtector size Nucleon KR-1i and KR-2i 36-40M42-54L...