The Casio MRW-210 is a great casual diver-style watch with a large readable dial and a resin case and strap. I originally reviewed it here in this post. The resin watch strap deteriorated over the last 9 years and eventually became unusable and the watch battery died. However, the case seemed to have plenty of life left and the other two issues are easily fixed. Here is a photo of the watch way back in the day when it was just a smoldering hotspot in my wallet.
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| Casio MRW-210H Analog Watch |
The nearest available Casio model on Amazon is the Casio MRW-200H Analog Watch available here via my Amazon affiliate link.
Replacing the Battery in a Casio MRW-210H Watch
The caseback came off easily with the removal of four small screws. The replacement battery number is 399 (SR927W or SR927SW). You can find it on our watch battery page.
| Casio MRW-210H Watch Movement & Renata watch battery |
On a cautionary note, every battery compartment seems to have a few metal bits designed to hold the battery in position and close the circuit so that power flows from the battery to the watch. I try not to bend any of the fiddly bits too much.
| Casio MRW-210H Watch Movement |
Replacing the Watch Strap on a Casio MRW-210H Watch
Since the old strap was gone, I ordered an inexpensive new one as a replacement. It's a cobee silicone watch band and it's available on Amazon for a less than $10. It is a silicone strap with plenty of adjustments and quick release spring bars to make installation easy and strap swaps a cinch. I bought the 20mm wide strap and it fit perfectly.
| Cobee Silicone Watch Strap (Amazon photo) |
If you'd like to take a look at this Cobee watch strap, use my Amazon affiliate link here.


