We're pretty impressed with these king-size stockpots; both the quality and the price are outstanding. They're made from a 3-layer sandwich of aluminum and stainless steel, aluminum in the center of the sandwich to conduct the heat quickly and evenly, the stainless steel as the "bread" to give you a rugged, non-reactive, dishwasher-safe surface that will look great forever. This 3-layer sandwich is not just on the bottom, it makes up the entire pan, bottom, sides and all. The lids are stainless stee, except for the 24-qt. which has a tempered-glass lidl. All in all, great stockpots.