Pure stainless steel: baking trays for oven is made of high quality 18/0 stainless steel without toxic materials and harmful substances, rust-resistant and healthful for your daily roasting and cooking, far superior to aluminium or Teflon non-stick sheet pans durable & non-warp: leak-proof seamless design and heavy-duty construction for added strength and even heat distribution, proper weight and feel reassuring sturdy when holding in hands, unbreakable and anti-deformation for long-lasting reliability.