TriMaxT technology using triple wall insulation. Double stainless steel walls with copper coating for maximum temperature retention. Vacuum sealed. Keeps hot for 14 hrs and cold for 72 hrs approximately. Includes stainless steel filter for tea # fruit or ice. The ReflectaT lid is insulated and coated with stainless steel # enhancing temperature retention # prevents drinks from touching plastic. The lid also has dual opening with a wide mouth for easy filling and a small mouth for drinking # a sturdy and flexible integrated silicone handle and a leak-proof seal. BPA free material. The width of the