Rust-Resistant Griddle InsertConvert your Weber grill into a griddle with the carbon steel Rust Resistant Griddle Insert. This cooktop is transformed under extreme heat and pressure that case hardens and bonds the surface, reducing the ability for moisture to collect and rust to form. Then it s pre seasoned with food safe oils that condition the metal for an extra boost of rust resistance and a natural, easy release cooking surface that makes it ready to use right out of the box.