Purchased new on July 3, 2025. Used twice since then and stored in a dehumidified cabinet with the lens. Please comment if you have any questions. From the official website: The CDF (Cinematic Diffusion Filter) is a camera lens filter that allows you to take high-quality photos and videos with a cinematic atmosphere by creating a matte, analog-like texture and impressive light diffusion. The L and S versions differ in their light diffusion strength, with the S version subtly expressing light. It's easy to use in any photo or video scene, and can be used as a regular protective filter due to its water-repellent and oil-repellent coatings.