TonePros KF6 guitar tuning machines are designed for the 6-in-line format. These tuners boast classic features but with performance in mind. F6B series guitar tuners pay critical attention to the all-important winding height, which is necessary for the split/top load design of yesteryear's 6-on-a-side tuners. Special clipped seven screw set based plates are included for classic vintage appearance. Classic matching finish metal buttons are standard for these tuners. Now you can retrofit your vintage guitar's tuning machines without the need to modify it physically.