Simply Choose Brand (either to match existing or because you want to upgrade) from the drop down menu above. All batteries are the same size and voltage, just the brand is different. We recommend the use of these Silver Oxide in watches which will provide a more stable operating environment. Technical Details: 1.55v Nominal 5.8mm Diameter x 2.15mm Known as: 379 SR521SW SR63 RW327 and can be used instead of AG0 / L521.
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