I have been using OEM cartridge sets in my Brother HL-3170CDW, both worked fine for a while and then became very weak when about 1/3 of the cartridge was left. I decided that an expensive OEM toner would do. I bought them not expecting much but they installed and registered perfectly with the printer. On the first test print, the colors were bold and vibrant, something I haven't seen from my OEM toner in a long time. Time will tell but I will continue to use EZ Ink toner. Even if they don't last that long, the price can be wrong.