By re-using many original Hewlett Packard W1331A 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 HP 331A component, designed to work in harmony with the other pieces.The completed remanufactured HP W1331A toner cartridge is then filled with a black toner powder produced to offer comparable results. With each remanufactured HP 331A unit offering the same 5,000 page estimated yield and coming fully guaranteed, we highly recommend this partially recycled Hewlett Packard 331A unit.