This is a vintage New Old Stock (NOS) Tiffen Adapter Ring, size 23.5-5 (commonly marked as 235). It is designed to adapt 23.5mm lens threads to accept Series V (Series 5) filters and accessories. The item comes in its original vintage packaging with clear specifications and function markings. Precision-manufactured in the USA, this ring is in unused condition—ideal for photographers using classic 8mm or 16mm movie cameras and specialized vintage optics.