It is glass. The label says, "Quantaray by Cokin" but the actual product does not have Quantaray anywhere on it. The model numbers are even the exact same as Cokin. The regular price before the clearance 30% was taken off was still less than the exact same thing that B&H or Adorama had. I almost got a star filter for it at Ritz, but I already have a star filter, so I thought it would be a waste.
This is the polarizing filter I got on clearance at Adorama.
http://www.cokin.com/filtres3.html?=#171 Seems like an interesting toy.