40S?

I believe it's an old designation for some kind of stainless, but I don't know much. Matweb.com comes up with various things including kinds of rubber and a tungsten-infiltrated silver contact material:

If someone who knows more than me doesn't respond I'd give them a quick call and ask what the heck they mean. It'll expose your ignorance, but I've found that doing so isn't always as bad as it seems, particularly if you can spin your response to make it sound like you just weren't familiar with some terminology quirk. It'll certainly be better than losing a customer because you were afraid to say anything.

------------------------------------------- Tim Wescott Wescott Design Services

Thank You Tim. Yes, I will be calling them shortly. Fear of exposing my ignorance has never slowed that part of the process. Appreciate the help. K.