We claim the ornamental design for a four hole swivel clamp, as shown and described.
FIG. 1 is a perspective view of a four hole swivel clamp depicting, in part, the new, original and ornamental design thereof.
FIG. 2 is a perspective view of the four hole swivel clamp showing the underside thereof.
FIG. 3 is a right side elevation view of the four hole swivel clamp of FIG. 1.
FIG. 4 is a left side elevation view of the four hole swivel clamp of FIG. 1.
FIG. 5 is a front elevation view of the four hole swivel clamp of FIG. 1.
FIG. 6 is a rear elevation view of the four hole swivel clamp of FIG. 1.
FIG. 7 is a top plan view of the four hole swivel clamp of FIG. 1; and,
FIG. 8 is a bottom plan view of the four hole swivel clamp of FIG. 1.
The broken lines in the drawing figures depict environmental structure or portions of the four hole swivel clamp for illustrative purposes only, and form no part of the claimed design.