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You can find an overview of the cartridges that fit your MFC-J6947DW here: https://support.brother.com/g...
The LC-3219XL, fit to the following devices: MFC-J6935DW, MFC-J5335DW, MFC-J5730DW, MFC-J5330DW, MFC-J6930DW, MFC-J6530DW, MFC-J5930DW.
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