1973 IWC Large Vintage Mens Caliber 150 Electronic Tuning Fork Watch - Stainless Steel Constellation Timing: Timed to precision in

Timing: Timed to precision in five positions on a state-of-the-art computerized system

When you're wearing it it feels as light as a steel dress watch

Movement type: Caliber 550/552

It is all-original down to the original crystal gasket and presents as a 9

Its sculpted tonneau case flows smoothly into the integrated bracelet like the body panels of a classic road-racing machine

1973 IWC Large Vintage Mens Caliber 150 Electronic Tuning Fork Watch - Stainless Steel Constellation Timing: Timed to precision inToday's offering features this very cool and rare IWC caliber 150 watch. For the movement the company used a patented tuning fork based movement made by ESA. These watches use a battery driven tuning fork whose vibrations are converted by a special index mechanism into an almost smoothless rotary motion of the hands. At the time, tuning fork watches were the most accurate timekeeping mechanisms ever devised. The tuning fork technology was so accurate