This genuine McCormick 6632821A1 fuel cap is an original equipment manufacturer (OEM) part designed for various McCormick X-series tractors, including X4.20, X4.30, X4.40, X4.50, X4.60, X5.20, X5.30, X5.40, X5.50, X6.420, X6.430, X6.440, X7.440, X7.450, X7.460, X7.650, X7.660, X7.670, X7.680, X8.660, X8.670, X8.680, and X8.690 models. It also fits a wide range of Landini 4, 5, 6, 7, and 8 series tractors. This essential component ensures a secure seal for the fuel tank, preventing contaminants and fuel evaporation.