Made of 18/8 stainless steel liner with copper coating vacuum sealed, this 28 oz tumbler is durable and rust-resistant. Double-wall vacuum insulated technology provide a good ability of insulation, which is good for keeping your drinks cold or hot for hours. Each tumbler comes with a spill-proof transparent lid and a drinking hole on the top for easy sipping. The convenient handle makes it an ideal tumbler that you can carry with you wherever you go. Large imprint area is perfect to display your unique brand and logo. Imprint drinkware only can be handwash. BPA FREE, FDA certified, CA Prop 65 list