You might have noticed that in all “Core” (i3, i5, i7, i9) series of Intel. The Processor names end in “K”, “F”, “KF” or None.

K: Unlocked for overclock but with integrated graphics card

F: Without integrated graphics card not unlocked for overclock.

KF: Unlocked for overclock but without integrated graphics card.

None: With integrated graphics card but not unlocked for overclock.