The Epson 33 cartridges fit in a number of Epson Expression Premium printers. In total, there are 5 different cartridges and that characterizes the Premium printer series. If your printer supports the 33 cartridge series, you can find the number in the product description, which states which printers are suitable so you don't order incorrect cartridges. You can choose from 2 brands, Epson and the private label brand Pixeljet. In addition, you also choose whether you want a separate black cartridge or a combo pack, so you have all colors immediately.