This is a large, flat stone that is placed on the bottom of the oven, or the bottom shelf if your oven has an electric element on the bottom. Baking stones are used to bake free-form bread loaves, flatbreads, and pizza, and mimic the heat of a brick or stone oven. The baking stone creates a dry and crispy crust by drawing moisture away from the crust as it bakes. The stone should be the thickest you can find, at least ½ inch thick, to hold heat better, and needs to be preheated for up to 1 hour before baking. - See more at: http://thebakingpan.com/baking-equipment/#breadtools