Abstract: An insulating slot liner for an electric motor. The slot liner includes a body portion having an exterior side configured to be disposed adjacent to an interior surface of a stator of the electric motor and an interior side opposite the exterior side. The slot liner includes a first arm portion and a second arm portion each extending away from the interior side of the body portion so as to form a winding channel between the body portion, the first arm portion, and the second arm portion The slot liner includes one or more insulation openings formed in the body portion between the interior side and the exterior side so as to form a fluid connection between the winding channel and the interior surface of the stator.