Model Compatibility: Canon imageRUNNER 3300 series (and compatible models) Function: The laser unit uses a laser beam to scan and expose the photosensitive drum, forming the image of the document to be printed or copied Technology: Utilizes a precise laser scanning mechanism for accurate image reproduction Location: Typically installed in the main body of the printer near the imaging drum Purpose: Transfers image data to the drum by exposing the drum surface to the laser light, which then attracts toner to the exposed areas to form the image