This I believe is a model train transformer. This has been in my family since the 1960's. It came to Arizona with us in 1971, has gone from apt. to apt. for the next 16 years, then to my garage in 1988 when I got married and bought a house. In my garage since then.
As a child we had Marklin (mit umlaut) trains, but I do not recall this being used with them. I seem to remember those were blue.
The trains are with another family member. Does it work? No promises, don't know.
Freely ask any questions. Usually ask to meet at a coffee shop 40th St and Greenway.