Made with a 304 stainless steel inner and a 201 stainless steel outer shell. With its convenient 17oz. capacity, this tumbler is perfect for enjoying your favorite beverages throughout the day. This thermos features a double-walled design with vacuum insulation. It is equipped with a screw-on/off lid that opens up to reveal a convenient push-to-open spout.The double-walled construction and vacuum insulation provide excellent temperature retention, keeping your drinks hot and cold for up to 12 hours. Customization is made easy with options for laser engraving, silk-screen printing, and more, allowing you to personalize the tumbler with your logo or design.