Had a dig in my rag-bag of assorted film gear and came across this lens. It is M42 mount and I also have a set of extension tubes and a 3x adapter. From the build it is clearly a macro lens with a deeply recessed front element (1:2 or 1:1 with tube). Have trawled the 'net and found Soligor is a house name for a US importer who sourced from various Japanese manufacturers including Cosina. Most of the range was zooms and I have only found one reference to the 55mm macro. Can anyone shed more light? Have ordered a M42 to M4/3 adapter so I can test it out (with a few other M42 lenses I have). It would not focus with stacked M42>OM>MFT adapters.