I purchased two toner cartridges from Laser Source. The cartridges were for my fax machine. The cartridges did not work. My fax machine blinked red lights and they would not stop. These cartridges were generics. I approached the rep for Laser Source and I requested that they fix the cartridges, replace them, or give me a credit. The president of the company did not want to be bothered. He gave me every reason under the sun why Laser Source could not fix or replace the cartridges. The bottom line is that Laser Source does back up their products. I wasted almost $200 on toner that does not work. Laser Source won't offer assistance to fix the toner or replace. The bottom line is some of their product does not work. They will give you every reason under the sun why they can't help you. In summary, don't take a chance with this company. If the toner does not work, you will be out of money with no hope of getting value out of your payment. Terrible customer service and this is a compliment!