I cannot for the life of me remember what the name of the piece of stone/marble/fake marble/plastic piece that is on the ground of the doorway many times into a bathroom. Does anyone know what this is called and where to buy these? Mine has cracked and I want to replace it but I don’t know where to buy them. I want my tile guy to be able to replace it when he is fixing my tiles in the bathroom. Help!!! I have attached a photo of the one at my office. This is not my broken one.