Primo Grills Ceramic Bottom PlateCeramic Plate Under the Charcoal Grate The Primo Oval XL Ceramic Refractory Plate is a replacement internal ceramic plate for the Primo Oval grills. If your original bottom ceramic plate is cracked, broken, or missing, this replacement part restores the inside of the grill back to its proper setup. This plate sits inside the lower body of the grill, under the charcoal grate, and is part of the ceramic system that helps protect the firebox area and