The ETA 2525 watch movement, introduced in 1977, is recognized for its thin design and notable features. With its automatic winding mechanism, sweep second function, and the inclusion of an hour angle disc, it presents a range of functionalities. Additionally, it incorporates a micrometer regulator and two serially coupled barrels, one with a fixed spring and the other with a slip spring. Notably, it lacks a date ring but offers a quickset date feature. A remarkable aspect of the ETA 2525 movement is its ability to maintain its reputation as one of the thinnest movements with date and sweep second functions even years after its introduction in 1977. Moreover, it boasts a hack feature. This watch movement has been utilized from 1977 onwards.