Convex Adapter is a tool for sharpening knives with the convex edge using Hapstone modular knife sharpener (R2, V8, M3). The convex angle difference can be set to the desired value.
Use the convex adapter instead of stock coupling to connect two parts of the guide rod.
Note. For other Hapstone sharpeners (R1, M2, K1, V7, V6), use the Convex Guide Rod instead.