Crafted with food-grade 18/8 stainless steel, this 40 oz thermos mug is durable and rust-free, allowing you to drink without worries. Featuring advanced vacuum insulation technology, the 40 oz water bottle exterior will keep your drink cold for up to 24 hours or hot for up to 12 hours., allowing you to enjoy icy cold drinks after intense workouts or a cup of hot coffee while winter camping. Travel and is perfect for the office, road trips, sporting events, gym, car, office, and at home. With a wide mouth opening, fit ice cubes, no problem! No metal taste whatsoever.