Ronda Caliber 513
|Diameter||11 1/2”’ (25.6mm) x 3mm thick|
|Battery Cell Number||371|
|Country of Manufacture||Switzerland|
||Ragazzo R1 (add yours to the comments below!)|
According to Ronda, the Powertech caliber 513 shown here should keep time within -10/+20 seconds per month. A fresh battery should get you about 45 months of use.
At the time of this post, replacement prices of $8.95-9.95 were found online.