Considering the weight on those - you're not getting much for your buck. You'd need to buy a couple of sets to flatten posters. Keep that in mind when you purchase.
I use these jawns. Grandmom always had them around the house just for decoration, and I always liked them. Checked out a yard sale, and bought 4 for a couple bucks each. Turned out one was signed, so I put it on eBay and got upwards of $600 for it. Used a couple bucks of that money to replace the one I sold. Tis why one is smaller.