The 30oz Stainless Steel Tumbler Car Cup is famous for rugged insulation, but a few simple habits keep it performing like new. After each use, rinse the 30oz Stainless Steel Tumbler Car Cup with warm water to prevent coffee oils from clinging to the electro-polished walls. Once a week, fill the 30oz Stainless Steel Tumbler Car Cup halfway with hot water, add a teaspoon of baking soda, and let...