Alpinestars S-R7 Helmet Liner Replacement helmet liner crown pad for Alpinestars S-R7 Helmet. OEM Sizing: XS: SM 12mm SM: SM 8mm MD: MD 8mm LG: LG 8mm XL: XL 8mm 2Xl: XL 6mm Optional Sizing: XS: SM 8mm, SM 12mm, SM 15mm SM: SM 8mm, SM 12mm, SM 15mm MD: MD 8mm, MD 10mm LG: LG 8mm, LG 10mm XL: XL 6mm, XL 8mm, XL 12mm 2Xl: XL 6mm, XL 8mm, XL 12mm