The McCormick 3671683M91 is a genuine OEM starter switch designed for reliable ignition control in various agricultural machinery. This 12V, 5-terminal switch features 4 positions (Off, On, Heat, Start) and ensures secure starting functionality. It is compatible with a wide range of McCormick, Massey Ferguson, and Landini tractor models, providing a direct replacement for the original component. Constructed for durability and consistent performance in demanding operational environments.