Ultimaxx Step-Up Ring 39mm to 40.5mm Black

What the ring does

This step-up ring adapts a lens with a 39 mm filter thread to accept a 40.5 mm filter. It is intended for photographers who own a 40.5 mm threaded filter and want to use it on a smaller-diameter lens. The ring adds no optical elements and maintains the original lens-to-filter distance. It does not serve lenses that already have a 40.5 mm or larger thread.

Thread compatibility limits

The adapter only bridges from 39 mm to 40.5 mm; it cannot connect to 43 mm or 52 mm threads despite references to those sizes in some documentation. Stacking multiple rings to reach larger diameters is not supported by this single piece. Vignetting may appear on ultra-wide lenses because the ring extends the filter plane slightly. Buyers needing a direct 39 mm to 52 mm step should choose a different ring.