Premium 18/8 food-grade stainless steel for durability and odor-free drinks. Double-wall insulation keeps beverages cold for 30 hours and hot for 12 hours. Spill-proof lid and non-slip base enhance portability and prevent leaks and scratches. Fits most cup holders, suitable for everyday use at home, office, gym, or on-the-go. Lifetime warranty against manufacturer’s defects ensures long-term satisfaction.