Older parts list noted a coal grate (the grate under the cooking grates) and lava rock as replacement parts. As part of our continued improvement program with all of our grills we no longer recommend the coal grates and lava rock. Not only is it expensive but it is messy and does not produce absolute best barbecue experience we can provide.
The updated replacement part is the flavor enhancers. These 304 thick gauge stainless steel devices just lay on top of your burners. They will take care of distributing the heat and reducing the amount of flair-ups you have on your grill.