Spread tempered chocolate on a 19.5cm x 12.7cm (7.5 inch x 5 inch) acetate. When set, cut 1.27cm (0.5 inch) vertically and wrap it around a 7.62cm (3 inch) ring mold and tape it, so it doesn’t move.
After the chocolate sets, carefully remove the ring from the acetate and you will have perfect chocolate rings.