Zojirushi stainless tumbler is made of high quality 18/8 stainless steel and will keep your hot beverages hot and your cold beverages refreshingly cold because of the superior heat and cold retention. Stainless steel Vacuum insulation minimizes heat transfer to keep the exterior from getting hot, and minimizes condensation when filled with ice cold beverages. The one-piece screw-off lid is easy to clean and prevents the loss of parts. It also has a handle designed for convenient carry. The tumbler has a special manufacturing technique applied to round the sip area for drinking comfort. The SlickSteel® polished stainless steel interior minimizes odors and stains. All parts are made of BPA-free plastic and stainless steel. 5-Year on heat retention.