Vaporizing panels sit above the burners of your grill. Once the holes start touching each other or you notice that they are touching, it is time to replace your vaporizing panels. The larger holes create hot spots in your grill and the heat is no longer evenly distributed. This is a set of 3 replacement vaporizing panels for use with AOG 36" grills. This set is compatible with both built-in and freestanding units.