Circular Satin-brushed “Jacob&Co“ Upper Bridge of the Tourbillon Cage; Bridges: Satin-finished, Hand-polished Angles, Drawnfinished Flanks; Black Finish Bridges on the Back; Mirror Polished Ornamental Plate with Circular Satin-finished Black Disc with Engraved and Whitelacquered “Jacob&Co.” Logo; Bridges set with 346 Brilliant- Cut White Diamonds (≈ 1.50ct.).