Switches manufactured by Schurter, Rafi, Omron and Diptronics, are used for such applications.
These keyboards can also accommodate LEDs of various colours and shapes. In fact low profile mechanical switches can also be offered backlit versions. Any solderable type of connector like Berg strips, FRC, Relimate, D Type etc. can be provided.
Here again as in Snap Dome keyboards, sealing can be achieved using industrial grade adhesives and such keyboard panels can be used in Machine Tool applications also.
Switch specifications for all the above mentioned low profile switches made by Schurter, Rafi, Omron, Diptronics etc., can be provided as required.