How can I tell how old my Gruen watch is?

To tell how old your Gruen watch is, turn it over and examine the back of its case. Most timepieces feature two numbers positioned side by side or one above the other. The first, or top, number represents the caliber number, while the second, or bottom, number is the style number. Once you have the style number, you can cross-reference it with trusted online resources to determine its age, and learn more about your timepiece. On 1stDibs, shop a range of Gruen watches.