The ornamental design for a slider for slidefastener, as shown and described.
FIG. 1 is a perspective view of the top, front and right of a slider for slide fastener showing my (our) new design;
FIG. 2 is a front view thereof;
FIG. 3 is a rear view thereof;
FIG. 4 is a top plan view thereof;
FIG. 5 is a bottom view thereof;
FIG. 6 is a right side view thereof, the left side view being mirror image thereof; and,
FIG. 7 is a reference view of usage thereof.
The portions of the article in broken lines are shown for illustrative purposes only and form no part of the claimed design. Chain dashed lines denotes boundaries between the claimed design and the portions of the article, that forms no part of the claimed design.