〇 This is an optional product compatible with the HHKB Professional series (Professional: 4 products, Professional2: 4 products, Professional2 Type-S: 2 products). 〇 60 replacement key tops for English layout model (only specific keys are not sold individually) 〇Please use it to replace the key top that has been damaged or has become dirty after many years of use. 〇 For the purpose of learning touch typing, you can replace the key top of the standard model (with engraving) with an unengraved key top. * Touch typing: Entering without looking at the key tops