Each setup block has a different thickness, and the thickness, height and depth of each gauge block are the same size. It comes with 7 precision setup blocks that can be combined to easily achieve different measurements. Set the height of your fence, blades, bits and other cutters in a fraction of the time. 4 in 1 Design-The woodworking Setup Bars can be used as a height gauge, depth gauge, square stacking gauge and an angle gauge. It is a combination of traditional depth and height gauges and traditional building blocks. Incredible Precision Gauge Block Set-Whether you're measaure your table saw blade or router, you will obtain high-precision measurement values. Router Table Set Up Bars are precise to ± 0.001-0.004inch.Height Gauge Set sizes: 1/8inch, 3/16inch, 1/4inch, 5/16inch, 3/8inch, 7/16inch & 12inch Solid Durability Gauge BarsSolid aluminum alloy material and anodized with a smooth finish can better protect your hands router bits and table saw, also have a long service life. Application: Easy to use in precision clamping of parts indrilling boring, milling, prinding, assembly work, etc.