Knob is made of plastic, the cap is made of Aluminum, not cheap ABS(Plastic)
Total Height: about 15.6mm; Outer diameter at the top: about 15.8mm; Outer diameter at the base: about 19.8mm
Fits Marshall Amplifiers with 5.8mm to 6mm Shaft Pots, these knobs DO not fit ‘D’ shaft Pots
Push on fit, no brass insert or set screw
Due to the wide variety of amplifiers and parts in the market, please be sure to verify the diameter of the pots on your AMP before you change the knobs for your amplifier