FIG. 1 is an upper front right perspective view of a base of a vertical foregrip showing our new design;

FIG. 2 is a lower front right perspective view thereof;

FIG. 3 is a front view thereof;

FIG. 4 is a rear view thereof;

FIG. 5 is a right side view thereof; and,

FIG. 6 is a left side view thereof.

The broken lines shown in the drawings represent unclaimed portions of the design and form no part thereof.