Fender Skirted Replacement Guitar Amp Knob Go to amazon.com Related posts Top 9 recommendation fender amp knobs FeatureReplacement Knob For Fender Amp and set screw.Retro Fit For Fender : 099-0930-000, for 1/4" shafts. DescriptionReplacement Knob For Fender Amp.Retro Fit For Fender : 099-0930-000.For 1/4" Shafts, set screw.