I don't know what those panels are, but they don't look like the equivalent of 703/705 type fiberglass. These appear much more solid, their absorption may be limited.
Also, that doesn't look like a very good deal.
A batt of 703 or 705 type board isn't super expensive, I can't recall what I paid for mine, probably less than a hundred bucks, and you get like a dozen sheets, obviously depending on the thickness. It really isn't very expensive. And it isn't super hard to find in any decently sized metropolitan area that has commercial HVAC/insulation supply houses around.
I wouldn't buy those, is what I'm saying, unless you find out what they are.