This wok with a 15 inch cooking diameter gives you extra capacity when you need it. The pan is a 3 ply construction of stainless steel on the exterior, a core of aluminum, and stainless steel on the interior. Traditional handles and rivets are also made of stainless steel. At the top of the polished cover there is a vent that may be opened or closed to control the amount of steam used when cooking. The edges of the wok are flared to form a perfect seal with the cover. The flat bottom makes this wok easy to use on your cook-top range.