KAISH 10pcs Guitar AMP Effect Pedal Knobs Pointer Knob with Set Screw Bronze Material: Plastic with Set Screw; Total height: 15mm; Base diameter: 19mm; Fits 1/4" (6.4mm) diameter pots For Effect Pedals or Amplifiers Quality Knobs with Screw Screw Metric Size is popular in guitars bass made outside the USA/Mexico. Great replacement for guitar amp knobs replacement