Adapt Convex Barrier Rings. Adapt Convex Barrier Rings can be used to help prevent ostomy output from getting under the pouch seal. They may be cut or stacked together to help improve the fit of a pouching system and are available in round and oval shapes to accommodate a variety of stomas. Adapt convex barrier rings can be used to create round or oval convexity, deep convexity when applied to a convex barrier, or flexible convexity when applied to a flat barrier. Features: Available in round and oval shapes, Flextend skin barrier, convex, Not made with natural rubber latex.