This lumbar support actually turned out to be a lot better constructed than I thought it would have, given the pricepoint. It's framed by a rigid metal structure, and the mesh material is probably the same grade that you would see in a high-end office chair like the Herman Miller Aero.
At first, the support almost seems to be too much, but as time has gone by, it's become more comfortable and really helps with keeping my back cool during these hot NJ summers. Highly recommended.
EDIT: I ordered a second one of these in 2010 after my original purchase in 2007 got snagged on something and ripped. It was somewhat easily fixed, but the edges were wearing from daily use, so I bought another. You'd think a product listed with the same exact title, which I found by searching my purchase history, would be exactly the same. Nope. The new version is completely inferior to the original - thinner metal frame, lighter weight fabric, overall cheaper feel.
If you look at the reviews in order of "newest first", you'll see a dramatic drop in ratings, likely due to the now horrible quality. It's unfortunate that the original reviews (for a different product) have convinced so many people to buy this piece of junk. I'm really disappointed that I can't get my hands on the original again - it was a great product at one time.