Shackle

FIG. 1 is a top-front perspective view of a shackle showing the claimed design;

FIG. 2 is a front view thereof;

FIG. 3 is a rear view thereof;

FIG. 4 is a left side view thereof;

FIG. 5 is a right side view thereof;

FIG. 6 is a top view thereof;

FIG. 7 is a bottom view thereof; and,

FIG. 8 is a bottom-front perspective view thereof.

The broken lines in the figures show portions of the shackle that form no part of the claimed design.

The screw pin in FIGS. 1 - 8 shown in a lighter color intensity form no part of the claimed design.