Hi John,
they do explain how oxygen is separated from nitrogen. I put a copy of the textfile in the attachment.
Hans
Sorry, I missed that description on the ELAN2 site. There are, of course, other ways to do it too.
I think the OP is missing the fact that these small LN2 plants are intended for small research and medical applications. One would not necessarily expect to find a price list, shopping cart, and instructions for using your Visa card to buy one. The companies don't want to waste time on non-serious inquiries or inquiries from locations to which they cannot ship. (I don't believe we know yet where the OP is located.)
The best advice, which has already been given a few times, is to call the company on a regular working day and ask the price. Be prepared to answer a few questions about intended use.
John