The McCormick 6513068M91 Fuel Tank Cap is a genuine OEM replacement part designed for various McCormick agricultural tractors. This essential component ensures a secure seal for the fuel tank, preventing contaminants from entering and fuel from spilling. It is compatible with a wide range of McCormick models including the X4.20, X4.30, X4.40, X4.50, X4.60, X5.35, X5.45, X5.55, X6.45, X6.55, X6.65, X7.440, X7.450, X7.460, X7.650, X7.660, X7.670, X7.680, MC100, MC105, MC115, MC120, MC130, MC135, MTX110, MTX120, MTX125, MTX135, MTX140, MTX150, MTX155, MTX165, MTX175, MTX185, MTX200, XTX145, XTX165, XTX185, XTX200, and XTX215 series, ensuring proper fit and reliable performance.