I bought this kit to add digital readouts to a diy cnc router. It represents a great value for this application, and the accuracy is far better than what is needed for woodworking, and is much better than the physical resolution of my steppers.This has made calibration of the steppers much simpler - I use Mach3, which has a calibration routine that sets the number of steps per inch by comparing a specified tool movement distance with actual physical distance moved. Having a DRO to measure the actual distance moved is a huge benefit, and I can be confident that the machine is set up to be as accurate as possible.The DRO panel and scales were shipped separately, and I initially received only the DRO panel. The seller responded immediately, and after a few emails were exchanged, a replacement shipment arrived with the scales. I am very pleased with the customer service, and would order from this seller again.Installation was challenging since my machine design did not take the mounting of the scales into account, but once done it works very well.One thing in the manual that I have not been able to get to work has to do with searching for reference points on the scales in order to allow for recovery of physical positioning of my machine if the tool is moved with the power off. It simply does not work as documented. It could be that these scales do not support this, I do not know. This is a fairly minor issue to me, but I can see how serious machine tool users might want this feature more than I do. (Edit) The benefit of this purchase has already made itself evident. While cutting a kind of tricky part with lots of concentric curves, I lost power due to a breaker tripping.