Customers returning to us after 30 years can rely on our database, as we do have almost all data of any propeller ever manufactured on file, which includes type as well as finished tolerances and CNC router data plus which person in our workshop had been involved making it. From the serial number we do these data can be recognized in our database. Thus we can make sure that you will get exactly the same propeller with the same or better performance if you wish than the one you bought maybe 30 years ago as one of our more than 15000 delivered propellers.