S-PRO1 Slim ND3.0 (1000X) ND Filter. We are very proud to offer the new Multi-Coated S-PRO1 filters. S-PRO1 range of filters build on their previous very successful filters. The S-PRO1 range are manufactured using same LEVEL OF Schott glass used in B&W & Heliopan filters. The multi coating features: Anti-glare. Anti fouling (repels oil, water etc). Scratch resistant. These coatings mean: Easy Cleaning. Reduced reflections to help prevent glare and ghosting. Fantastic durability. The filter ring is coated using an Anodic oxidation matte black to greatly reduce reflections. Slim filter frame with double threads, meaning it"s perfectly compatible with wide angle lenses. SPECIFICATIONS: Filter Size: 77mm. Frame Profile: Slim. Filter Density: ND3.0 (1000x). fStop Reduction: 10 (approx). Double Threaded: Yes. Multi-Coated: Yes (3 Coatings). Optical Material: Quality same as Schott Optical Glass. Frame Material: Aluminium. Usr review: Matt Welke --Hey guys I have been doing some research on trying to find the best ND filter long exposures in 77mm. There are only a few brands out there that make these filters. Heliopans run highest price and B+W are in the middle. I came across another brand I noticed one called Haida which go for 1/3 cost which is half the price, but I could not find much research on them. After extensive google searching I found out that these are excellent filters compared to B+W. I know there are others out there that likely want more information on them so I will post what I have found out here. Im about to purchase the CameraPlus filters, I did no research on the Heliopans as they are out of my price range. There are 2 major concerns when purchasing a ND filter: 1 is color cast and 2 is IQ degredation. Haida works out smartly as B+W.