This tube socket is very rare and unusual in design. Made around 1922 by JRH Radio, it has a built-in wire wound reostat to adjust filament voltage. You adjust a knurled 3 in. Ring to get the voltage you need. Reostat measures in rotation from .8 to 7 ohms. Make a nice socket to display 4 pin early tube.

Condition: excellent for age. No cracks. Color: black. Material: bakelite. Metal parts are polished nickel plated brass.

Feel free to ask any questions. Check out pictures. Magazine ad is for reference only and not included in sale.

Sold as is and no returns. USA customers only. Thank you.