Three Layers Programmable & Nkro. Despite The Three Layers Programmable Mode, Fn1/Fn2/Fn3, All Kinds Of Keyboard Key Function Could Be Set Through Driver, Macro Record, Personalize Your Own Function Keys As You Wish. Onboard Flash Memory Unit Could Save The Configuration To The Keyboard If Offline. The Sk61 Is N-Key Rollover, Freely Enjoy It Without Any Conflict While Pressing Multiple Keys