ETA test watches are used to test specific features of the watches, such as function and durability. The ETA-Test-Prototypes have been made in 1988-1995 and they also include a small number of prototypes of Swatch Chrono, Scuba or Automatics. ETA test watches were never meant to leave the factory. Again they were only made for tests. I have seen many ETA tests, even ones that were sawn in half.