Selling here a top class swiss IWC Schaffhausen automatic watch, model Grande Square compressor, equipped with the movement C.8541b, with 23 jewels and 5 pos. adj. and temperature, as it's marked onto it. Case big size 35mm, a very beautiful and rare "tonneau" shape, which fits onto the caseback by a sort of unique mechanism. Caseback marked on the inside with ref. no. 8-72 and also the brevet that is implemented into it (not sure what is that though...). The inside mechanism is a real jewel, chronometer and all inhouse, every component and function is being developed by IWC in the factory. It's chronometer grade and runs at a low frequency of 19800A/H, thus ensuring a longer autonomy, but precision is also at top, it does not lose even 1 minute in 24h, but merely a few seconds. Glass has a scratch near the 7 hour index, but nothing serious. Comes with a leather box very good quality of a same-famous (if not more...) watch brand, just as it can be seen in last photos, and with its certificate of authenticity.