Here are a few great options I found for black toner cartridges for the HP pro 400 laser printer: The HP 80A Black Laserjet Toner Cartridge is the original HP cartridge available for R2816. It's highly rated and will give you reliable printing performance. The HP 80X Black High Yield cartridge is also original HP and available for R4312 - it's a better value if you print a high volume. Both would be excellent choices to keep your HP pro 400 laser printing great documents. Let me know if you need any other details on these cartridges!
