Tri-ply cookware is made up of 3 layers of material sandwiched together, we use an inner core of Aluminium which is superconductive allowing great heat transfer and precise temperature control and this is sandwiched between food-grade SS304 stainless steel which is made from a 60% recycled SS430 stainless steel outer layer and an interior layer of SS304 stainless which is over 50% recycled and both food safe and easy to clean, which is over 50% recycled material. This makes our pans compatible with all heat sources, especially induction.