Initially I thought it was a simple silicone keypad, but after seeing a video of the unit, I'm a bit confused. What sort of button is behind such a click?
I THINK there's backlighting on the unit, so that has to fit in somehow as well.
That is a fully custom keyboard, so normal catalog keyboard switches do not apply. The soft function buttons on the left of the screen sound like tac switches. The main keyboard switches have a deeper tone, maybe because they are attached to a larger pc board. Another but less likely is that it is a silicone keypad with a synthetic click sound and mechanical thump as feedback.
So not off the shelf type button, the question is, any idea what type button it is likely to be? There is a distinct click which doesn't sound like a dome switch which.
I have an older decca mechanical nav display that has pushbuttons on the front and long extensions rods behind that go to standard V3 microswitches.
Much like what ian said.