Its designed just for that. They have them at mostly at speed facilities like Athletic Republic (google it) and some universities. I'm not a big fan of them.
Seeing as I have never seen one of these before, nor heard of their use for actual training, what purpose do they serve? It seems like the risk/reward isn't high enough to me.
And Wiggs, were you a state level runner? The highest I was clocked was at 22 mph back in high school doing state 400s, and I was still getting beat. Funny, track is the only reason I wish I had done the college route some times. I was noticeably faster at 22-23 than I was at 17-18.