The ornamental design for a fastener for sight, as shown and described.
FIG. 1 is a perspective top view of my new fastener for sight;
FIG. 2 is a top plan view of my new fastener for sight of FIG. 1;
FIG. 3 is a bottom plan view of my new fastener for sight of FIG. 1;
FIG. 4 is a side elevational view of my new fastener for sight from the right side of that of FIG. 3;
FIG. 5 is an end view of my new fastener for sight of FIG. 1;
FIG. 6 is a side elevational view of my fastener for sight from the side opposite that of FIG. 4; and,
FIG. 7 is an end view of my fastener for sight from the end opposite that of FIG. 5.
The broken line showing of the portions of the fastener for sight in FIGS. 1 through 7 is included for the purpose of illustrating environmental structure and forms no part of the claimed design.