Found at my grandmother’s house — there are rotating discs inside with numbers printed on them. What are they?”

 What you’ve got there is a vintage mechanical counter brooch—most likely used as a knitting or crochet row counter (sometimes also called a “chatelaine counter”).

🔍 How it works

The small rotating discs with numbers are used to keep track of counts.

You’d turn the discs manually to record progress (like rows, stitches, or repeats).

The pin on the back lets it be worn on clothing, so it’s always handy while working.

🧶 Why it looks decorative

Back in the late 1800s to early 1900s, practical tools were often made to look like jewelry:

This shell/feather design suggests it could be Victorian or early 20th century style.

Women would wear these as part of a chatelaine (a set of tools clipped to clothing).

🧭 Could it be something else?

Less commonly, similar pieces were used as:

Small calendar trackers (day/month)

Score counters (for games)

But the design + numbering format strongly points to a needlework row counter.

💡 Bottom line

👉 It’s basically an old-school version of a digital counter—a wearable tool to keep track of numbers while knitting or crocheting, disguised as a beautiful brooch.

If you want, I can help estimate its age or value more precisely 👍