Made in the USA from hard anodised aluminium which will never rust, they have patented raised rails with a flat base plate interspersed with holes for airflow. It is this design that amplifies the heat and eliminates hotcold spots, whilst the bottom plate protects food from flare-ups. In addition, drippings are vaporised in the valleys adding flavour and moisture to the food. The raised rails create perfect sear marks on food, however, you can reverse the panels if you wish to use a flat griddle surface.GrillGrate sets are designed to sit on top of the existing grate when being used in a charcoal grill, but as a replacement for the stock grate in a gas grill.