ProMaster ステップアップリング（37mm→52mm）

Fit my 37mm lens perfectly and the threads are smooth, no cross-threading issues at all. This little ring lets me use my bigger 52mm filters without any wobble.

This step-up ring threaded onto my 37mm lens perfectly, no wobble at all. Finally lets me use my larger 52mm filters without buying new ones. The precision machining seems solid for the price.

Metal threads feel solid when screwing on, no wobble or cross-threading like some cheaper rings I've tried. It does exactly what it should for adapting my 37mm lens to 52mm filters, though I wish it came with a tiny wrench for extra grip when removing it.