The Bronx 900 ml tumbler is made from RCS certified stainless steel and has a double-walled vacuum construction with copper insulation. Keeps drinks cold for 48 hours or hot for 12 hours. The lid has a dual function with a collapsible straw for easy sipping, and a flip-top opening with a convenient folding handle for effortless portability. Fits most car cup holders. Packed in a recycled cardboard gift box.