4" - 1" Aperture Converter Box, Metal

Finally found a solid metal adapter that actually fits snugly without any wobble. The machining on the threads is precise and smooth, so swapping between apertures takes seconds.

Was a bit puzzled on how to mount it at first, but the metal construction is reassuringly sturdy once you figure out the alignment. It does exactly what it says for stepping down from 4 inches to 1 inch.

The all-metal body feels way more solid than the plastic adapter I had before, no flex at all when I bolt it on. Swapping from the 4-inch down to the 1-inch opening took maybe a minute, and the threads lined up clean.