The ornamental design for a pair of shoulderstraps for a carryingdevice, as shown and described.
FIG. 1 is a front perspective view of the pair of shoulder straps for a carrying device of my design;
FIG. 2 is a front elevation view thereof;
FIG. 3 is a rear elevation view thereof;
FIG. 4 is a left-side elevation view thereof;
FIG. 5 is a right-side elevation view thereof;
FIG. 6 is a top view thereof; and,
FIG. 7 is a bottom view thereof.
The longer evenly dashed broken lines, which show a carrying device and portions of the pair of shoulder straps, form no part of the claimed design. The dot-dash broken lines define a boundary of the claimed design. The shorter evenly spaced broken lines represent stitching, which is included in the claim only when shown on solid line surfaces.