I claim the ornamental design for a bra with interchangeable back strap, as shown and described.
FIG. 1 is a rear perspective view of a bra with interchangeable back strap, showing my new design;
FIG. 2 is an exploded rear perspective view thereof;
FIG. 3 is a front elevational view of the design as shown in FIG. 1;
FIG. 4 is a rear elevational view of the design as shown in FIG. 1;
FIG. 5 is a left-side elevational view of the design as shown in FIG. 1, the right-side elevational view being a mirror image thereof;
FIG. 6 is a top plan view thereof;
FIG. 7 is a bottom plan view thereof; and,
FIG. 8 is a front perspective view thereof, illustrated with the back strap in a flat configuration. The back strap is shown separately for clarity of illustration.
The broken lines showing a person in FIG. 1 depict environmental matter and form no part of the claimed design. The finely-incremented broken lines shown on the back strap are lines of stitching.