This double-walled tumbler offers all the benefits of stainless steel.Up to 24 hours cold and 8 hours hotDouble-wall vacuum insulation and copper lined 18/8 stainless steel with leak resistant & easy-close lidDo not put tumbler in dishwasher, freezer or microwaveHand wash with soap (no bleach or chlorine) & water using a scratch-free spongeLid is dishwasher safe (top rack only)