Pyrex Professional Large Flat Cookie Sheet Large cookie sheet made of commercial-weight steel for fast, even heating Markings take the guesswork out of amount and placement of cookie dough Extra-wide edge provides a secure grip even when wearing oven mitts Dishwasher-safe; oven-safe to 350 degrees F; metal-utensil safe Measures 16-1/2 by 13-1/2 inches; limited lifetime warranty