The Bintiva bottle is crafted from the highest quality materials, and incorporates a unique design so that it never leaks, or leaves any condensation or seat on the exterior of the bottle. Unlike some other brands, the Bintiva stainless steel water bottle is made with food grade, type 304, 18 8 stainless steel on both the inside and the outside of the bottle. This provides the user with a bottle will not rust, leak, or have any residual metallic taste. It is also 100 percent free from BPA phthalates and other harmful metals and toxins commonly found in plastic and aluminum bottles. The bottle is double walled and has a vacuum seal between the walls to keep the beverages inside hot for about 12 hours or cold for about 24 hours. The vacuum also prevents the user s hand from the heat or cold inside the bottle.