Weber # 80624 Lower Cooking Grate for 18-1/2" Smokey Mountain Cooker Weber # 80624 Lower Cooking Grate, for the 18.5" Smokey Mountain Cooker, '10. The grate measures 17" in diameter, not 18.5. It fits in an 18.5 grill. This cooking grate has a thirty pound weight limit. Please visit Weber's website at http://help.weber.com/schematics/#serial-number to ensure you order the correct parts for the specific year of your grill model. Parts can appear to be identical but not fit certain year models. It is best to look up by serial number. The link will also help you find the alpha-numeric serial number.