This pack of two Fender Stratocaster S-1 Switch Control Knobs comes with two push on knobs and no caps, these are for use with an S-1 switch potentiometer (which can be retrofitted to nearly any US and Mexico made Stratocaster manufactured from 1954 to present). The knobs feature a knurled edge for grip, and it is a great way for you to customise the look of your strat. Will fit 1/4" split shaft S-1 switch potentiometers.