*The inner tank is made of stainless steel, the material is hard, the color is bright, it will not rust, the real safety and hygiene, the use of peace of mind.*The built-in filter is a 304 filter. The filter is cleaner and easier to clean. It is easier to clean dirty and difficult to wash tea stains..* The lid of the cup has a built-in seal that can be removed and cleaned, is easy to clean, and can be sealed for food grade silicone. It is non-toxic and safe..* Sleek cup mouth, soft lips, exquisite craftsmanship creates this unusual experience.* Anti-corrosion, anti-rust, easy to clean, drink healthier and safer. The teacup is also selected from stainless steel, precisely uniform filter holes.