Description:Suitable for both hot or cold, your beverage will taste its best and holds its temperature longer in our Calypso tumbler, made of high quality 304 recycled stainless steel, with Leak proof ?�lid Stainless steel is a highly sustainable material due to its recyclability. It has one of the highest recycling rates of any metal, with over 90% of it being recycled worldwide. This means that stainless steel can be melted down and reused in the production of new products, reducing the need for new mining and extraction of raw materials. Additionally, stainless steel's long-lasting durability, low maintenance requirements, energy efficiency, and versatility make it an environmentally friendly choice. Its use can help reduce waste, conserve resources, and minimize the carbon footprint of products and processes. It can't get more sustainable than that !