It is a very accurate 4 wheel alignment instrument that will measure the camber, castor and toe-in to within 1/100 of a degree.
If your car is wrong then it will pull on the steering and wear tyres quickly. My car failed the KDS alignment because it was impossible to adjust even at maximum adjustment. This meant that new suspension struts have had to be fitted.
I get the car back tomorrow. It seems that even after new front suspension not all cars can be corrected. These cars must wait for a new suspension component that will be available sometime in the Spring.
My cars steering was improved by the KDS realignment, but noy cured.
No choice, you get what you are given. No charge though.
Due to strong cross winds on my camber free road I am unable to make a decision as to the pull now that new suspension has been fitted. If there is a pull it is now weaker as the car now always drifts to leeward.
I will test ASAP and report back.