[Hallicrafters] Crystal question

[w3wjr at comcast.net]

I want to order a crystal for my HT-32mkI so I can move transmit into the 28-28.5mhz. band space. I think I need 32.mhz. crystal, but that part is in my books.

I have ordered a crystal or 2 in the past, I know the seller is going to ask some questions but I can't recall what they were.

So I am asking the collective wisdom of this group for more information.  What do I tell this guy I want when i call to order the Crystal.  Case type? PPM? Other questions?

Thanks
W3WJR