1. The head can be adjusted from 0 to 70 and fixed every 5 times (+22-1/2 and 67-1/2) to give you an accurate reference angle and length respectively.Close tolerance indexing pins. The pin snaps into place, giving you confidence that it's in place. 2. Both edges of the blade are engraved with 1/32Inch inch graduations. regular raises 3. The ruler has a total cumulative error of .004Inch over the length of the blade. 4. Almost any project can be done. Saw blades have the same special teeth. 5. There are notches every sixteen inches throughout the blade. 6. Just place the pencil in the notch and slide the tip along the edge of the pencil to get a perfectly parallel line. Colour:As Shown Material:Metal Size:15 Inch/10 Inch/20 Inch Package Contents: 1 x Woodworking Ruler Only the above package content, other products are not included. Note: Light reflection 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.