As one of the most successful one-lens-fits-all, the Tamron Adaptall-2 system was produced from 1979-1989. For many adapters in this system, it's straightforward to use. However, Tamron does have some special notes on how to install the adapters for Penax KA, Ricoh P, Konica AR, Leica R4/R4S/R4SII. Therefore, a manual in the following image is very helpful.
Over the years, the price of these used adapters, for most camera mounts except Pentax KA and certain rare mounts, is falling . In today's digital era, the aperture size can be set via Pentax DSLR if a KA adapter is used.