Fastener

FIG. 1 is a left side elevational view of a fastener, showing my new design;

FIG. 2 is a front elevational view thereof;

FIG. 3 is a perspective view thereof;

FIG. 4 is a right side elevational view thereof;

FIG. 5 is bottom plan view thereof; and,

FIG. 6 is a top plan view thereof.

Broken lines show portions of the fastener that form no part of the claimed design.