This versatile kit will cover most 40%, 60%, 65%, TKL, and custom mechanical keyboards. It offers HHKB (MX mount) compatibility with the 7u space bar, bottom row keycaps, and extra shift keycaps in sizes 1.25u, 1.75u, 2.00u, and 2.25u. For 40% compatibility, there’s an R2 1.75u, two R3 1.25u, an R3 1.50u, two R4 1.00u, and an R4 1.75u keycap. Finally, there are convex 1.00u, 2.00u, 2.25u, and 2.75u keycaps to be used on split space bar builds. The keycaps from the numpad can be used to complete several layouts.