The ornamental design for a sockretainingdevice, as shown and described.
FIG. 1 is a top perspective view of a sock retaining device showing the claimed design.
FIG. 2 is a top view of the sock retaining device of FIG. 1. The bottom view is a mirror image of FIG. 2 and is, therefore, not shown.
FIG. 3 is a side view of the sock retaining device of FIG. 1; and,
FIG. 4 is a top perspective view of the sock retaining device of FIG. 1.
The broken lines in FIG. 4 illustrating the socks are provided for the purpose of illustrating the environment in which the sock retaining device is used and to designate unclaimed subject matter that forms no part of the claimed design.