Base

FIG. 1 is a top perspective view of a base showing my new design; FIG. 2 is a front elevational view thereof; FIG. 3 is a back elevational view thereof; FIG. 4 is a left elevational view thereof; FIG. 5 is a right elevational view thereof; FIG. 6 is a top plan view thereof; FIG. 7 is a bottom plan view thereof; FIG. 8 is a bottom perspective view thereof; and, FIG. 9 is a top perspective view shown within an environment of use. The broken lines shown in the drawings depict portions of the article and form no part of the claimed design. In FIG. 9 , the broken lines depicting wheels are showing environmental subject matter that forms no part of the claimed design.