Think outside the square box and you'll end up with hexagonal keycaps. Or HEX keycaps actually. They work with regular Choc switches and obviously need a keyboard that is designed with these caps in mind (such as the 0xC.Pad macropad for instance)
The caps are made from semi-translucent white POM, much like the MoErgo MCC keycaps, and work exceptionally well on boards with a per-key backlight.
If you want to design a board for these keycaps, you'll need 21.5mm horizontal spacing and 18.62mm vertical spacing. The caps themselves are (side to side) 20.96mm wide.
These caps are shipping in packs of 10. If you order 1 pack, you'll get 10 keycaps.