The tumbler is a 20 oz double wall 18/8 stainless steal copper vacuum insulated tumbler with clear push-on lid. The vacuum insulated body and copper lated inner wall help retain the internal temperature of the tumbler longer. The copper plated inner wall ca make the difference of 9 over 24 hours and prevents heat from entering or exciting the tumbler by thermal radiation.
Hot 8 Hours Cold 16 hours