The McCormick 4221378M1 is a genuine OEM rear left lamp designed for various McCormick X-series tractors. This essential lighting component provides reliable illumination for the left rear of the vehicle, enhancing operational safety and visibility in diverse conditions. It is a direct replacement part, ensuring perfect fitment and performance for compatible models including the X4.20, X4.30, X4.40, X4.50, X5.35, X5.45, X5.55, X6.420, X6.430, X6.440, X7.440, X7.450, X7.460, X7.650, X7.660, X7.670, X7.680, X8.660, X8.670, and X8.680 series.