it's an exhaust cutout bypass. Places like JC Whitney and Summit sell them. they are controlled by a cable, it lets you bypass the exhaust to run it open. This isn't legal in all states, or on emission controlled vehicles.
If you run one, it's at your own risk. Besides, not enough backpressure running an open exhaust; these were made for muscle cars.
You would need some serious mods for that to be useful at the dragstrip, just get a nice header/exhaust combo, you'll make more power in the long run.