Replace a broken or worn socket knob with these black plastic socket knobs. With black classic styling suitable for a variety of table and floor lamp fixtures, the ridged knob design makes it easy to turn lights on and off. The socket knobs come with 1/2 inch extenders to position the socket knob further away from the socket, if necessary. These socket knobs and extenders are tapped 4-36 thread size for easy replacement knob installation.