Manufacture of reference 3417 was launched in 1958 and ceased around 1968. It was Patek Philippe's first "Anti-Magnetic" wristwatch made in series, available exclusively in stainless steel. At the time of its launch, the "Amagnetic" feature was a sign of superiority and consequently mentioned on the dial. With the standardisation of improved shock proof and anti-magnetic balances in the early 1960s the inscription disappeared.
The first series were fitted with a cal. 12 AM 400 movement, as of 1960, the calibre 27-AM 400, such as the present watch, was used until its discontinuation in the late 1960s. This later movement bears the Patek Philippe patented Gyromax balance.
For further details and illustrations of reference 3417 see Patek Philippe Steel Watches by John Goldberger, pp. 342-349.