Cartridges Unlimited’s Compatible Laser Toner Cartridges and supplies for HP 400 M451nw are designed to offer best print performance, dependability and consistent yields that meet or surpass HP OEM (Original Equipment Manufacturer) specifications for the HP 400 M451nw and offer high-quality output. These compatible toners are brand new and are a smart alternative to high-cost OEM HP laser toner cartridges, offering substantial savings over the HP 400 M451nw supplies.