ProMaster ステップアップリング（37mm→49mm）

The threading is smooth and precise, clicks right into place without any wobble. I used it to mount a 49mm filter on my 37mm lens, and it holds tight even with a polarizer.

I was worried about vignetting, but the aluminum build keeps it slim enough that my 49mm filters sit flush with no dark corners.

Threads perfectly onto my 37mm lens and holds the 49mm filter snugly with zero wobble. I’ve used it for a few shoots and the precision machining shows—no cross-threading or play at all.