The best pizza you will ever have!! The Big O Pizza Steel is made out of 1/4 inch plate and is 11 inches in diameter. The steel will need to be seasoned prior to cooking your pizza (comes with seasoning instructions). The Big O Pizza Steel is Made in the USA. The Big O Steel fits in the Original Orion Cooker and the Large Orion Cooker. It does not fit in the Small Orion Cooker.