I don't know if you're asking foreign or cavity. There are patterns, side plates, steel rings and movable type blocks in the cavity. The shell has an upper ring (upper guard ring), an upper cover, an arc block (slider), a middle die sleeve and a base (lower guard plate). Small accessories of the upper cover include small gaskets and pads. The small fittings of the bow seat are guide rods and lifting blocks (T-blocks). The middle sleeve is provided with a middle sleeve wear plate, and the base is provided with a base pad. . . . . . The whole shell also has connecting screws.