Empire ET-1 Step-Up Transformers. Used in-line with MC cartridges to amps or receivers with MM-only selectivity. Was rummaging through some old phono stuff here and found them as-new in the box with instructions and specs. Don't know anything about them, other than they function well. Cool, too.

Photos:

http://www3.sympatico.ca/conlonp/Empire1.JPG

http://www3.sympatico.ca/conlonp/Empire2.JPG