Allows 77mm threaded filters to be used on lenses with 52mm standard filter threads. Features a durable brass frame. Knurled sides provide an easier grip. Designed to prevent binding and jamming, making it easier to remove than standard aluminum step-up rings. Has an anti-reflective treatment inside the frame to minimize reflections. Features a matte black finish. The anti-reflective treatment is intended to make the ring suitable for long exposures. The adapter is precision-machined. The matte black interior and anti-reflective treatment are designed to absorb rather than scatter light.