2449R Series 2Ref

Widely considered a masterpiece, the 2499 combines a chronograph with a perpetual calendar and features a more robust case than the 1518. Its four production series include: square buttons with Arabic numerals (1951-1955); round buttons with baton or Arabic numerals (1955-1960); round buttons with baton numerals and 5-minute divisions (1960-1978); and round buttons with baton numerals, seconds divisions, and a sapphire crystal (1978-1985). The pink gold version shown was sold by Christie's.