Orrco 60143 Extension Socket Knob 1/2 Inch, Black, 2 Count

On/Off Replacement Knob

Hard-to-Find Fastener 014973143640 Thread Lamp Turn Knobs, Black, 10-Piece

Angelo Brothers 70161 Replacement Knobs

Extension Socket Key Brs 1/2in

Leviton 7090-PG Medium Base Complete, Aluminum Shell Incandescent Lampholder, Removable Turn Knob, 2-Circuit, for 3-Way 2-Filament Lamps, Brass