This product is a set of four compatible toner cartridges designed specifically for HP printers in the 212X series. The toner cartridges come with chips and are suitable for use in models W2120X, W2121X, W2122X, and W2123X. These black toner cartridges are essential for achieving high-quality prints using laser print technology. The unit quantity of four cartridges ensures that you have an ample supply for all your printing needs.