Fat Daddio's Oblong Sheet Cheesecake Pan (Rectangular) with a Removable Bottom is made with 16-gauge anodized aluminum and features a reinforced top to prevent warping with a 1/2 inch flange on all 4 sides. The completely seamless square-bake design means Fat Daddio's cake pans and baking pans have no seams or weld lines often found in other pans. Anodizing completely seals the aluminum, making a smooth scratch-resistant surface, and ensures there is no cross-contamination or leaching of aluminum into foods. Anodized aluminum is also non-reactive with acidic and dairy ingredients. Fat Daddio's anodized aluminum bakeware, baking pans and cake pans are precision engineered to offer excellent baking performance, even heat distribution, and durability. Bottom included. Dishwasher safe. Lifetime warranty.