Notice:Option (edge finder) for the whole set Why is the concentricity different every time the probe is installed?Because your chuck spring clip cannot 100% uprightness. Every time the probe is installed, even if the concentricity is adjusted to 1 wire, there still be deviations when the probe is removed and installed again. How to distinguish the three wires?The red wire is VCC, the black wire is GND, and the white wire is IO. So your chuck is AAA and above accuracy (concentricity less than equal 0.005), because many chucks in China have false standards, it is recommended to use a high- gauge or steel rod to check the table after installing the chuck. Look at concentricity. It's best to place the dial indicator at a distance of 50mm from the chuck, which is roughly the distance between the ball head of our probe and the root of the tool handle., Manufacturer: PokFhgur