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That p/n is for a Harmony remote.
This may well (most likely) be the battery to replace in your remote:
For this type of 'flat slab' battery, like a cell-phone's battery, you will need to open the case on the Harmony remote. Perhaps there is a sliding hatch, perhaps there are screws to remove to open the case. I'm not sure which, for this model of remote (the Harmony 900 perhaps?)