According to one embodiment of this disclosure a core includes a first end and a second end spaced generally opposite from the first end. The core further includes a stacking axis defined between the first end and second end and a first toroidal structure located between the first end and the second end. The first toroidal structure includes a first passage extending through the first toroidal structure in a first direction that is perpendicular to and passes through the stacking axis. The core also includes a second toroidal structure located between the first toroidal structure and the second end. The second toroidal structure includes a second passage extending through the second toroidal structure in a second direction. The first direction and the second direction are oriented along the stacking axis at a non-zero degree angle with respect to each other.