Extension Socket Knob 1/2 Inch Go to amazon.com Related posts Top 10 best lamp knob replacement part 2019 Feature1/2" extension2 lamp knobs (4/26"F x 4/36"M)Black knobs/brass extensionsCarded/2 DescriptionSocket Knobs Replace Pk22 lamp knobs (4/26F x 4/36M). 1/2 extension. Black knobs/brass extensions. Card/2.