One of the most popular items in the line is their Kiwi lid. This version is the extra-small size with a diameter of 4" (set of 2 pieces). This Charles Viancin silicone lid seals tightly on smooth rims. The lid works well on smooth rims of stainless steel, glass, plastic, and melamine for example. We've also used it on glazed stoneware with good results (Le Creuset stoneware and Emile Henry for example).