I don't quite understand the question Gianni, so I'll answer both things it could be. :)

The index ring around the dial, showing 1/5 of a second markings, is separate from the dial. The dial itself is composed of a "sandwich" of a number of plates, effectively pressed together so as to be permanently sealed. So although the registers appear marginally lower than the rest of the dial face, the manufacturing process results in the dial becoming a single unit - in this case, then, the registers are not separate from the dial.

Hope one of those answers your question!