Patek philippe,' Ellipse Horizontal, Ref 3581' wristwatch, circa 1970, the midsize 18ct white gold wristwatch with manual wind movement, dark blue dial, applied textured indexes, 18 jewels, monometallic balance, adjusted to heat and cold, isochronism and five positions, elliptical shaped case, bezel set with thirty six round brilliant cut diamonds, on a black leather strap, case, dial and movement signed, case number 2701195, calibre 23-300, movement number 1211132, width 32 mm.