What do I have here?

[Trigger]

I read on the 'net last night that there are basically two types of CP filters - "Ground" and "Precise" glass (Ground being the cheaper, less desirable ones).

I have this particular filter, but it gives no indication either way:

http://www.shoptoit.ca/techpro-ds-67mm-circular-polarizer/34216955/

It is made in China, and retailed for $70.00. Should I assume that it is the "ground" type? It says "Pro Quality", but these days, that means about as much as "Natural" or "Organic" on a food label.