The ornamental design for a two-sided ring, as shown and described.
FIG. 1 is a side isometric view of a two-sided ring;
FIG. 2 is a front elevation view thereof;
FIG. 3 is a rear elevation view thereof;
FIG. 4 is a left side elevation view thereof;
FIG. 5 is a right side elevation view thereof;
FIG. 6 is a top view thereof; and,
FIG. 7 is a bottom view thereof.
The two-sided ring has a unique design of two flat-sided surfaces that provide a locking mechanism to keep the ring in one position when worn on a finger.