This set of LxTek remanufactured HP 934XL and HP 935XL ink cartridges has been professionally refurbished. Using our own patented methods, each cartridge has undergone a rigorous process of cleaning, restoration, and refiling. Furthermore, each cartridge was methodically tested to ensure full working condition and a superior print quality. This is a truly cost effective alternative to OEM cartridges. We are certain that you will love our cartridges, and that is why all LxTek branded products come with a 1 year warranty.LxTek