This adapter is new, unused, CNC made from solid brass and chrome finish, is rangefinder coupled from 0.7m/ 2 feet up to infinite, have internal mount for 50mm classic Zeiss Contax lenses.

The focus rotation way and helical pitch is the same of Leica lenses.

This adapter is 6 bit code compatible.

I has been making this adapters for 20 years, you can find references on Internet as Amedeo Adapters.