This is a set of two silicone caps specifically for DURALEX Picardie glasses. (Glasses not included) The vibrant light green caps can also be used as coasters, and are apparently called "Glass cap and Coaster." They are made of a silicone-like material, similar to a Tupperware lid, and seal tightly. After purchase, I have been using the glasses daily, but I rarely used these caps. I have discarded the packaging, so I don't know the exact model or part number. The glasses shown in the photos are for reference only and are not included in the sale. The diameter of the lid is approximately 9 cm. The size of the glasses shown in the photos are amateur measurements. (Not included in the sale. For reference only) Mouth diameter: 8.5 cm Bottom diameter: 5 cm Height: 9 cm Capacity: 250ml Duralex