Purchased these and I’ve got to say… Don’t do it! These are really cheap in quality. I actually broke one just trying to put it together. Guess that’s why they give you three. The metal is really soft, they are a real hassle trying to put them together, and you have to tighten the screws so much so it will stay the way you need them angled that my fingers are sore as anything! Love Woot! to death but this deal wasn’t worth it at all. I’ll be going to RadioShack to buy a better set.
I bought one of these from Amazon a while back, and the same thing happened. The metal ring that holds the magnifying lens snapped while I was assembling the arms, and it was all Humpty Dumpty from there.