For insulated water bottles, build quality is directly tied to how well the bottle performs in maintaining beverage temperature. Premium construction features double-wall vacuum insulation, which creates a near-complete airless space between the inner and outer walls. This design allows drinks to stay cold for up to 24 hours or hot for several hours, depending on the bottle. https://oliver-wine.blogspot.com/2013/09/10-vergelegen-flagship-red-2005-75cl.html