Mifab is a newer manufacturer of drains, established in 1982 in Chicago IL. They haven’t been around long enough to have obsolete drains yet, but they did change their model number system. They are also one of the few manufacturers that have always put part numbers on their drain rings, though that is changing as most manufacturers are now trending that way. Their product is similar to Watts in design, in fact the poly domes for their large roof drains are identical. Rings and CI Domes differ though. They also usually have very good stock on other products such as downspout boots, scupper sleeves and downspout nozzles etc. Items that are pretty much identical between all manufacturers.