Gotta love the descriptive text on the company website:
"The Model 121 Series is virtually impervious to contaminants found in the harshest applications, both indoors and in the field. It's Ruggedized/Militarized design withstands the rigors of even the most hostile and demanding industrial and military environments. Vital electronics and switch bearing surfaces are sealed for long-term protection against water, beverages, dust, dirt, and many chemicals. Sugar based beverages can be left to dry without causing damage to components."
Heh!
Might make an offer on one of these, they do look massively robust. I'm guessing that they can be made to work with a Microsoft PC? Looks like a relatively standard connector, maybe a DB-9.