Interesting leveling blocks

You have buy the plastic wedges and then add your own lumber. I already have the lumber and chocks, (lots of lumber). I see no advantage to these over anything else that already exists. If you have your own lumber already, you already know you don't need these plastic wedges. All you have to do is taper the edge of the lumber and you've got the same thing.

Nay, I pass on this one.