HP 94A (CF294A) Black Compatible Toner Cartridge Canon ImageClass MF644Cdw From massive savings and consistent From massive savings and consistent page yield to reliable printing performance and shopping convenience this Compatible Brother TN436 4 Piece Combo Pack is definitely a wise buy for your office school or home printing needs including the Canon MF660 Series and LBP640 Series laser printers (see full compatibility list below) Our toner cartridge meets or exceed that same page yields set by ISO standards with the HP brand and at 5% yield should print out 1200 pages per toner Our brand of toner will not void your printer warranty and ours comes with a 1 year warranty and money back guarantee