This is a rare masterpiece from the early 1990s manufactured by International, called "Ingineer" Ref.IW3508. It features a black dial and is a scarce 500,000A/M model. By using a zirconium alloy hairspring instead of the previous soft iron inner case, it achieved a 500,000A/M anti-magnetic resistance. However, due to its vulnerability to durability and temperature changes, it was produced for only a short period from 1989 to 1993.
With a case diameter of 34mm and a thickness of 9mm, the IW3508 is relatively small in size but still offers a high anti-magnetic resistance of 500,000A/M and water resistance up to 120 meters, earning it the nickname "Skinny Ingineer." It is a rare piece, as the combination of a stainless steel case and stainless steel bracelet is said to be limited to only 614 pieces, available in both black and white dials. It is powered by the Cal.37590 movement, featuring a 5-position adjustment 21-karat rotor. The package includes a repair estimate from 2011 and a spare bracelet.