Base cover

FIG. 1 is a top, front and left side perspective view of a base cover on a dental chair showing our new design;

FIG. 2 is a top, left and rear side perspective view thereof;

FIG. 3 is a top, right and front perspective view thereof;

FIG. 4 is a top plan view thereof;

FIG. 5 is a left side elevational view thereof;

FIG. 6 is a right side elevational view thereof;

FIG. 7 is a rear side elevational view thereof; and,

FIG. 8 is a front side elevational view thereof.

The broken line showings of internal portions of the base cover form no part of the claimed design. The bottom of the base cover forms no part of the claimed design. The broken line showing of the dental chair illustrates the environment of the claimed design and forms no part thereof.