The steel knob is a complement to Le Creuset's cast-iron casserole from the Signature series, which features fenol buttons. If the cast iron pot is to be used in the oven, we recommend replacing the phenolic button on the pot with a steel knob. The steel knob can withstand all temperatures. The steel knobs are made of stainless steel and comes with a screw for mounting in the package. Note that the steel knob becomes hot, so we recommend using potatoes / griddles for cooking and serving.