Gently used but I have so many water bottles and coffee mugs that I don’t reach for this too often. Very clean inside. From the S’well website: -Therma-S’well® Technology with triple-layered, vacuum-insulated construction designed to keep beverages colder or hotter, longer than all the rest. -18/8, food-grade stainless steel. -Condensation-free exterior that won't sweat in your hands or bag. -BPA/BPS-free and reusable. -Hand-wash only.