That is the correct term, it does work as it should, the price is WAY too high.
Look here for the knock offs if that's the route you really have to go..
http://www.1337tactical.com/shop/productlist.php?typeId=1
You'll find that while this stuff is fine for range use, it's not going to last you as long as the real deal will... There are some that will attempt to debate that with me by saying, well it's lasted fine so far (year later, range only gun) and yeah it might. But I'm a buy once cry once guy and it you take the time, save a little more you'll see that it is indeed worth it.
The caveat is and will be that this is a great way to figure out if you prefer a certain style of optic. I did this with red dots and fake ACOG's.
All my humble opinion of course.. 5 AR's and many thousands of dollars later, just hoping that some won't have to learn the same lessons I did.