Single USB Card Holder

FIG. 1 is a perspective view of a single USB card holder. FIG. 2 is a top view of the single USB card holder. FIG. 3 is a first side view of the single USB card holder. FIG. 4 is a second side view of the single USB card holder. FIG. 5 is a bottom view of the single USB card holder. FIG. 6 is a third side view of the single USB card holder; and, FIG. 7 is a fourth side view of the single USB card holder. The broken lines in the drawings immediately adjacent the shaded areas represent the bounds of the claimed design and depict portions of the single USB card holder that form no part of the claimed design.