ETA offers four grades of watch movements:
These ratings may vary between specific caliber numbers, but here are the specs for the popular ETA caliber 2824-2:
One way to distinguish between Standard/Elabore and Top/COSC grades of ETA movements is to look at the anti-shock device on the balance wheel:
Standard and Elabore Grades:
Nickel plated balance wheel; Nivarox hairspring; polyrubies used for pallet jewels.
Top and Chronometer Grades:
Glucydur balance wheel; Anachron hairspring; red rubies used for pallet jewels.
Despite differences in accuracy and testing, all grades share some common specs and features. All grades have the same diameter, height, jewel count, lift angle, frequency, and power reserve.
Difference in finishes coming soon.