I claim the ornamental design for a high heel base, as shown and described.
FIG. 1 is a perspective view of the claimed design.
FIG. 2 is a front elevation view thereof.
FIG. 3 is a rear elevation view thereof.
FIG. 4 is a left-side elevation view of the claimed design.
FIG. 5 is a right-side elevation view thereof.
FIG. 6 is a top plan view thereof; and,
FIG. 7 is a bottom plan view thereof.
The invention pertains to an ornamental design for a high heel base. The solid lines represent the bounds of the claimed design, whereas those features shown in broken lines form no part of the claimed design.