PMI (Precision Models Inc.) was a subdivision of Model Power, one of the big importers of model railways in the USA. The PMI range incorporated mainly items manufactureds by Lima, that's why some people think PMI means "precision models from Italy". Now, this is wrong. PMI sold their trains in their own packaging which looked like this:
Most of the range was standard Lima with NMRA couplings, but they also had a few exclusive freight cars with load which were not sold by Lima.
CB&Q (Burlington Route) gondola with Löwenbräu beer kegs (PMI catalogue number 6736)
Pennsylvania Gondola with insulated FS-Italia containers (PMI catalogue number 6741)