According to the Dell website, this is how the cartridges for the Dell All-In-One Printer/Copier/Scanner Model AIO A940/A960 are supposed to look like. (see attachments) Black cartridge P/N: 7Y743 with U-shaped "lump" on the (black) lid. (equivalent to Lexmark "82") Color cartridge P/N: 7Y745 with square with corner cutout "lump" on the (blue) lid. (equivalent to Lexmark "83") BUT, the black Dell cartridges have the identical corner cutout "lump" as their color cartridges. In other words, they have the lid from the color cartridge, but in black instead of blue. Both cartridges are made by Lexmark and rebranded for Dell. But Dell made the black cartridge intentionally with a different "lump", so customers are forced to buy expensive Dell cartridges. Stupid actually, because now the black and the color cartridges each fit in the other's slot! Beat Dell at their own game, don't pay their rip-off prices! When you open that Dell printer, lift the black lever that closes over the black cartridge. From the underside of that lever you will see a small "pin" sticking out, that corresponds with the corner cutout "lump" (as depicted on the color-cartridge). Cut that pin off with a sharp knife or a wire cutter. All of a sudden, the cheaper Lexmark "82" black cartridges fit in (and any other remanufactured equivalent). Money in your pocket! PS: the color cartridges from either Dell or Lexmark or whomever fit normally, and are all the same with the same "lump".