This is a SIGMA WR CERAMIC PROTECTOR 67MM. I'm selling it because I haven't been using it much. I've heard about potential swapping, so I'm sorry, but returns are not accepted. Please note that there may be scratches on the lens case. The following is an excerpt from the product description: The world's first* filter using glass ceramics has arrived. It's the birth of a "true protector" that can protect your precious lenses. Interchangeable lenses are the most important element in photographic expression. As a key device for image creation, they should be the most important asset for the photographer. To help you use your valuable interchangeable lenses for a long time, what can Sigma do? From that perspective, Sigma believed that "protective filters" should also be developed and realized based on their own standards. In filter development, from an unprecedented collaborative relationship with a glass material manufacturer, a "true protector" made of a completely new material was born. The Sigma WR* CERAMIC PROTECTOR uses "clear glass ceramics," a highly reliable protective filter. Clear glass ceramics uses high-strength glass ceramics (crystallized glass), which is also used in the aerospace industry, and is a new material that achieves the transmittance required for optical equipment. It has ideal properties for protective filters, such as higher hardness than conventional chemically strengthened glass and greater flexibility than sapphire crystal glass. *WR: Water Repellent