Best Materials - The mug is made of durable non-stain, heat-resistant borosilicate glass Keep the Warmth - Lid keeps tea warm while brewing Leak proof - The Lid doubles as a trivet to prevent dripping BPA Free - This set complies with the FDA and LFGB food standards and does not contain BPA Environmental Friendly - Make Taste, Not Waste is Bodum’s motto. Our goal is to reduce the ecological footprint in the world, our products are durable, made with the best materials. We don’t design or use any kind of disposable products, our objective is to have products that last.