5 piece height measuring devices of different sizes and 2 piece hole gauges, can easily set the height of the fence, blades bits and other cutters according to the needs, which is faster and more accurate than using a combined ruler.Stack setup bars compatible with a wide variation or sizes, or use on their own, work and measure quickly.Set up gauge blocks are all 2-1/2 inches long, diameter of 2 pcs round block hole gauges respectively: 1/2inch and 10mm, 5 pcs square block respectively: 1/2inch, 3/8inch, 1/4inch, 3/16inch, 1/8inch. Accuracy: +/- 0.03mm (less than 2 mils=less than 0.05mm)Easy-to-read laser-etched labels on each block. Fitted case included, so it will be more tightly protected during transportation.7 pcs Blocks Solid Aluminum Construction Black Anodized to better protect router bits and saws.colour: blackMaterial: aluminumSize: length: 2.5 inches about 6.3cmPackage Contents:2 x Setup Blocks Hole Gauges5 x Setup Blocks Bar Gauges Only the above package content, other products are not included.Note: Light shooting and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.