(Embossed in center) S
This U.S. patent was issued on February 5, 1929 to Christian Hendrik Jasper of Rotterdam, Netherlands, assigned to Naamlooze Vennootschap Electricitate-Maatschappy "Electrostoom" of Rotterdam, Netherlands.
The wire nut is 1" tall x 1/2" wide.
Color: Brown
Material: Seems to be Bakelite