FIG. 1 is a front, top right perspective view of a chin strap buckle sleeve showing our new design therefor;
FIG. 2 is a bottom, rear left perspective view thereof;
FIG. 3 is a left side elevational view thereof;
FIG. 4 is a right side elevational view thereof;
FIG. 5 is a top, front view thereof
FIG. 6 is a top, rear view thereof
FIG. 7 is a top plan view thereof;
FIG. 8 is a bottom plain view thereof; and,
FIG. 9 is a bottom, rear left perspective view thereof, with dotted lines showing how a buckle may be located in the chin strap buckle sleeve, the portion shown in dotted lines being included for illustrative purposes only, and forms no part of the claimed design.