The NiSi Pro 40.5-43mm Aluminum Step-Up Ring is a precision-machined accessory that allows for the use of 43mm filters on lenses with a 40.5mm front thread. Finished with a matte black anti-reflective coating to prevent internal flare, this ring provides a secure and stable connection for your creative filters. Its slim design is ideal for maintaining the compact profile of mirrorless camera systems, offering a simple and effective way to expand your creative options without the need for multiple filter sizes.