You don't need to have heavy steel oven trays to be sure that they wont warp. Lakeland's all-purpose Hard Anodised Oven Tray is made of lightweight aluminium that's toughened by the hard anodising process to make it more than sturdy enough to withstand the highest temperatures as you make a really crispy batch of roast potatoes or bake fillets of fish in minutes. All Lakeland's trays and roasting tins are coated in Teflon nonstick so that food comes off easily, without any scratching, and they're really easy to clean. Oven safe to 250°C.