US D417570 S
FIG. 1 is front elevational view of a chair back showing our new design;
FIG. 2 is a rear elevational view thereof;
FIG. 3 is a top plan view thereof;
FIG. 4 is a bottom plan view thereof; and,
FIG. 5 is a left side elevational view, the right side being a mirror image thereof.
The broken lines shown in FIGS. 2 and 4 are for illustrative purposes only and form no part of the claimed design.