Dasco Pro AF300-2V Angle Finder with Two Magnets Made of high carbon steel that has been heat treated Molded of high impact plastic and allow the user to read any angle instantly and accurately from 0-Degree to 90-Degree in any quadrant Accurate to within 1/2 of 1-Degree Not affected by magnetic fields, cold or heat Angle and grade chart on back shows angles in degrees and converts them to pitch per inch and pitch per foot