4-Pack Set Screw Style Aluminium Potentiometer Knobs 1/4" Universal Top Hat Knobs Bell Volume Tone Control Knobs for Guitar/Bass/AMPS/Preamps BlackCNC machined universal 1 4" innder diameter knobs with set screw; Compatible with most solid shaft, split shaft or "D" shaft pots. When you install them on split shaft pots, please make sure align the set screw parallel to the split gap to avoid crashing your pots shaft Top hat design for most guitars and basses (Include import or American series Strats or Les Pauls as well as many other models ). Fit Guitar Bass Amplifier Preamps Power Amplifier or