The McCormick 86017148 control knob is a genuine OEM replacement part designed for various McCormick X-series agricultural tractors. This essential component ensures reliable and precise control within the cabin, maintaining the original functionality and ergonomic standards of your machinery. Compatible with models including the X4.20, X4.30, X4.40, X4.50, X4.60, X4.70, X4.35, X4.45, X4.55, X4.65, X4.75, X5.35, X5.45, X5.55, X5.65, X5.75, X6.420, X6.430, X6.440, X6.460, X7.440, X7.450, X7.460, X7.650, X7.660, X7.670, X7.680, X7.690, X8.660, X8.670, and X8.680. This knob is crucial for maintaining the operational integrity and user experience of your McCormick tractor.