To upgrade or downgrade the lining of your Arai helmet, you can order the lining in different strengths. Please, take the standard strengths of your helmet from the following table: Inner lining Helmet size Inner lining strengths XS 10mm S 7mm M 10mm L 7mm XL 7mm XXL 5mm for VX-Pro Junior Dry-Cool Inner Lining (100% polyester) easily cleaned