Klean Kanteen's quest to find and replace single-use items knows no bounds. These stainless steel, double-walled, vacuum insulated tumblers are perfect for replacing those single-use paper or plastic cups. Keeps your drink hot in the winter, and cold in the summer. Since the interior is electropolished, as well as stainless steel, this cup doesn't retain or impart flavors. Easy to wash, durable, with a lifetime warranty. Almost too good to be true!