The ronde solo preserves the perfectly pitched classical elegance and signature cartier features of the ronde de cartier watch that serves as its inspiration roman numerals blue sword shaped hands winding mechanism crowned with a sapphire and rail track minute circlesteel case steel circular grained crown set with a synthetic spinel cabochon sapphire crystal silvered opaline dial roman and arabic numerals sword shaped blued steel hands steel bracelet quartz movement cartier calibre 6