ifilter Air range of filters build on their previous very successful filters. The Air range are manufactured using same level of Schott glass (Schott glass is 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. SPECIFICATIONS: Filter Size: 49mm. Frame Profile: Slim. Double Threaded: Yes. Multi-Coated: Yes (3 Coatings). Optical Material: Quality level of Schott Optical Glass. Frame Material: Slim Aluminium.