HP LaserJet ADF Maintenance Kit. HP printer maintenance kits ensure your HP printer remains in working condition and continues to provide you with the highest print quality possible. This kit is easy to install and is designed to work with your HP Color LaserJet CM6040 Printer series. Ensure your HP printer continues to provide you with optimum print quality with periodic replacement of supplies. HP maintenance kits help ensure your HP printer is always available, helping to maximise your business efficiency. HP maintenance kits include user-replaceable parts that work with your HP printer to prompt you when they require maintenance.