Shoei Rf-Sr Center Pad Replacement center pad for Shoei Rf-Sr Helmets. Center Pads are only interchangeable within shell sizes (Xs-Sm, MD, LG, and Xl-2Xl). Features OEM Sizing: XS: 13Mm SM: 9MM MD: 9MM LG: 9MM XL: 9MM 2Xl: 5MM Optional Sizing: XS: 13Mm SM: 9MM MD: 9MM LG: 9MM XL: 9MM 2Xl: 5MM XS Helmets: SM 17Mm for a tighter fit, or SM 5MM or SM 9MM for a looser fit SM Helmets: SM 13Mm or SM 17Mm for a tighter fit, or SM 5MM for a looser fit MD Helmets: MD 13Mm for a tighter fit or MD 5MM for a looser fit LG Helmets: LG 13Mm for a tighter fit or LG 5MM for a looser fit XL Helmets: XL 13Mm for a tighter fit or 2XL 5MM for a looser fit 2XL Helmets: XL 9MM or XL 13Mm for a tighter fit