Replacement knob for a variac transformer, although it could be used for many other applications.

Designed to look look like the original bakelite knob. Kind of Art Deco-ish. Kob includes a pointer extending from the base.

Fits a 3/8 inch diameter shaft

Has two set screw holes for securing to shaft. Each setscrew requires a standard 8-32 x 1/2" machine screw and flat nut.