This new system goes 1 step further by matching the hi spot of the tire to the low spot on the rim to get rid of your wobbling, shaking tire. Not all garages have this but "times they are a changin'!"
The distance from the rim up to the curve of the tread used to be quite a distance and it was relatively flexible. Today, tires are much lower profile. The distance from the rim to the top of the tread is less and the sidewall is much stiffer. This means that minor problems can be amplified and transmitted into the car and you feel things a lot more than you used to.
But everybody says alright, we’ll balance the tires. That’s part of the equation but balancing isn’t always the answer. So you have to go a step further. What we have here is a Hunter Road Force balancer. This takes it to a new level.

We’re going to take the high spot of the tire and match it against the low spot of the wheel. It’s really more complicated than that, but to make it understandable… that’s what we’re doing. And it’s telling us here that we have 15 pounds of road force in the tire and if we swapped the tire around, moved it around on the rim, such as it’s showing us over here, that we can reduce this to 8 pounds total.
That brings us in spec and that means now we’re going to have a smooth riding tire.
If you are having issues with your tires whether it be low profile or not, seriously consider this before buying new tires, or even doing an alignment. Not all garages have this!

From: Road Force Balancing |*MotorWeek