The McCormick 6618878A1 Gasket Kit is an essential OEM replacement part designed for various McCormick X-series agricultural tractors. This genuine gasket kit ensures a proper seal and optimal performance for compatible models, including X4.20, X4.30, X4.40, X4.50, X4.60, X4.70, X4.80, X4.90, X5.20, X5.30, X5.40, X5.50, X5.60, X5.70, X5.80, X5.90, X6.420, X6.430, X6.440, X6.450, X6.460, X6.470, X6.480, X6.490, X7.440, X7.450, X7.460, X7.650, X7.660, X7.670, X7.680, X7.690, X8.660, X8.670, X8.680, and X8.690 models.