Came across these today in an antique store. They are porcelain wire twist on connectors so would fall in the 'Electrical Porcelain' bucket. They have green ink transfer markings and are marked NORMAL SIMPLEX with two Patent Dates, Pat. No. 1513656 and Pat. No. 1700985. Have never seen these before, not that I've gone looking for them. I know some of us have a shelve or two of non pin type funky electrical stuff. These will feel right at home on mine.