Seals used within lead passageways of implantable medical devices for creating a seal to implantable medical leads inserted into the lead passageways include a body defining a lead passageway with an axial dimension. The body further defines a first circumferential protrusion extending radially a first distance into the lead passageway, and the body further defines a second circumferential protrusion separated from the first circumferential protrusion along the axial dimension. The second circumferential protrusion extends radially a second distance into the lead passageway, the second distance being less than the first distance. The body further defines a first circumferential depression immediately adjacent the first circumferential protrusion and between the first circumferential protrusion and the second circumferential protrusion.