https://novoflexus.com/stepping-ring-for-retro-reversing-rings-82mm/
Stepping Ring, RETRO-Reversing Rings (STEP-RING-58/82) | Novoflex
Novoflex 82mm stepping ring for RETRO-reversing adapters for lenses with filter threads other than 58mm and provide best photography experience to...
stepping ringretro reversingringsnovoflex