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 circlecase in stainless steel beaded crown set with a synthetic spinel cabochon sapphire crystal silvered opaline dial 12 roman numerals blued steel sword shaped hands steel bracelet self winding mechanical movement with calibr