Patent ID: 8136681

Claim:
A stem comprising: a circular base having a circular outer perimeter centered on a center point of the circular base; a plurality of outer ears protruding outwardly from the circular outer perimeter; and a plurality of outer uprights being respectively connected to each of the plurality of outer ears at a bottom end of each of the plurality of outer uprights, the plurality of outer uprights being substantially parallel with each other and being substantially perpendicular to the circular base; a circular inner perimeter on the circular base, the circular inner perimeter being centered on the center point of the circular base; a plurality of inner ears protruding inwardly from the circular inner perimeter, the circular inner perimeter and the plurality of inner ears defining an opening in the circular base; and a plurality of inner uprights being respectively connected to each of the plurality of inner ears at a bottom end of each of the plurality of inner uprights, the plurality of inner uprights being substantially parallel with each other and being substantially perpendicular to the circular base.