By re-using many original HP 331X parts, this remanufactured alternative keeps the quality of print from your mono laser printer high. Whatever cannot be recycled, is replaced with a top quality compatible Hewlett Packard W1331X component, designed to work in harmony with the other pieces.The completed remanufactured Hewlett Packard W1331X toner cartridge is then filled with a black toner powder produced to offer comparable results. With each remanufactured HP 331X unit offering the same 15,000 page estimated yield and coming fully guaranteed, we highly recommend this partially recycled HP 331X unit.