PFU Color Key Top Set (HHKB Professional series only) PD-KB400KT01 With color key top, typing will be more fun! Please arrange the keyboard according to your taste. It is an option product compatible with HHKB Professional series (PD - KB 400 W, PD - KB 400 B, PD - KB 400 WN, PD - KB 400 BN, PD - KB 420 W, PD - KB 420 B, PD - KB 400 WS, PD - KB 400 WNS, PD - KB 420 WS). Please use to exchange key top of ESC (blue) key, Control (red) key. High Standard High Quality Material