FIG. 1 is a perspective view of the buckle of the present design.

FIG. 2 is a top plan view of the buckle of FIG. 1.

FIG. 3 is a bottom plan view of the buckle of FIG. 1.

FIG. 4 is a left side elevation view of the buckle of FIG. 1.

FIG. 5 is a right side elevation view of the buckle of FIG. 1.

FIG. 6 is a front elevation view of the buckle of FIG. 1; and,

FIG. 7 is a rear elevation view of the buckle of FIG. 1.

The broken line showing of a strap is included for the purpose of illustrating environmental matter and forms no part of the claimed design.