Double layer nonstick Coated interior enhances durability, and provides greater protection of the stainless steel against salt-containing beverages like sports drinks | | Heat retention: 180 DegreeF at 6 hrs/ 144 DegreeF at 24 hrs | | Cold retention: 45 DegreeF at 6 hrs | | Made of BPA-free plastic and 18/8 stainless steel | |