Yes he is talking about the Integy one.
A tweak board will show if you have more weight on one side of a the car than the other (a condition known as "tweak").
I have a MIP tweak station. It has a bubble sight glass and to be honest, I wasn't very impressed. It just isn't very sensitive. I could push down on my car while it was on the tweak station and get a different reading everytime. I would suspect the laser light set up would be the same,,, not that good.
You can get a digital scale. I bought one from Wal Mart. You can find them in the grocery department. The digital scale is more accurate AND I can weigh my car on it. You can't do that on a tweak station.
With the scale though, I did have to have to cut some boards so that I could set one wheel on the scale and the other 3 on the boards and have everything level. But that wasn't too hard.