Cool Toner provides replacement printing supplies with the same quality as OEM products with big savings. Package Included: 4 Pack Cool Toner Compatible HP 201X CF400X CF401X CF402X CF403X toner cartridges. Note: Please be informed that this product is COMPATIBLE MODEL, NON-OEM High Page Yield: 2800 Pages for Black and 2300 Pages for color at 5% coverage (Letter/A4)Compatible Printers: HP Color LaserJet Pro M252dwHP Color LaserJet Pro M252nHP Color LaserJet Pro MFP M277dwHP Color LaserJet Pro MFP M277nWarm Tips1. How to clear "Non-HP Print Cartridge(s)" error? It is a common error when you install compatible toner cartridges, but you can simply pressing "OK" or "?" button to bypass that and proceed to print. 2. How to deal with toner cartridge(s) not recognized your printer? Check if your printer model matches what the toner cartridges are compatible to. Turn off your printer, and then turn it back on after 30 seconds; install the cartridge again. For color toners, make sure you install the color toner cartridges into the right slots of your printer. If toner has a chip, clean the dusty chip of the toner cartridge with an eraser and reinstall afterward. Check if the sealing tape is pulled out entirely from the toner cartridge. If any of your toner cartridges have physical damage when unboxed, please contact us for replacement. Cool Toner have top notch product quality; to ensure that, our manufacturer have strict quality control and tests. 1. Cool Toner cartridges are certified with ISO9001, ISO14001, ROHS, STMC and CE, MSDS. 2. All of the products are up to withstand adverse environmental challenges.