Our 40oz bottles are made of lightweight recyclable 18/8 stainless steel and feature double wall vacuum insulated technology. This technology prevents condensation on the outside of the bottle, known as sweating, and keeps your preferred beverage toasty hot or icy cold for hours. The wide mouth design fits our flip and straw lids depending on your preferences. All caps and bottles come in a wide variety of fun and vibrant colors to choose from to make your bottle your own.