Model Compatibility: Canon imageRUNNER 6000 series Function: The DP unit helps apply the right amount of toner to the drum in the imaging process, ensuring high print quality with sharp text and images Color: Black (as it applies to the black toner) Purpose: Ensures that the developer roller is properly charged, which is necessary for transferring toner onto the drum and then onto the paper during printing Location: Installed in the developer unit assembly within the printer