I believe it is the same as the Sportrack, which was just purchased by Thule. I read this on a 4runner forum and it looks and measures the same. I believe this is it...
easier spot for a spare while off-roading , gives you a place to mount things, like hi-lift, shovel, etc. Also I've gone camping and ran out of space in the bed, and with the short bed, you can fill it up pretty quick hauling stuff.
Mine just got here. I think I'm going to coat it with some spray on bedliner first just for S&G's and throw it on the roof rack until I come up with some bed bars.