FibraMent-D is made from a proprietary blend of heat resistant and conductive raw materials approved by NSF International for use in baking ovens. This baking stone will provide even, direct heat from the bottom of the stone. Consistent thermal conductivity ensures that your breads and pizza will bake more evenly and in less time. Baking stones do NOT draw moisture out of the dough. Rather, good quality baking stones bake through the dough at a even pace. FibraMent-D never needs to be removed from your oven, bakes the perfect pizza, breads and bagels every time and easy to follow baking instructions are provided. Designed for gas, electric and convection ovens, it can be placed directly on your oven rack. FibraMent is safety tested and certified by NSF International, the widely recognized and respected independent certification organization for public health and safety. We cannot accept returns for the Fibrament Baking Stones because they are really heavy and shipping is expensive. But, rest assured, if a stone arrives with a crack, we will replace it immediately free of any charge. All you will need to do is send us pictures. Chips around the corners and edges of the stone do not change its effectiveness.