Gasket of fuel tank cap (MZA) - Simson Note.: Inner diameter: 40 mm, thickness: 3.0 mm Can be used for: Simson S50, S51, S70, SR50, SR80, SR2, Star SR4-2/1, KR50, Schwalbe KR51/1, Schwalbe KR51/2 The product of the MZA, which is the exclusive holder of the SIMSON brand.