The Charles Leonard Protractor Plastic, 4-Inch, Pack of 12 is the perfect tool for young mathematicians to accurately measure angles. Made of clear plastic, this protractor features an open center and sunburst at the base, making it easy for students to identify angles from 0 to 180 degrees. The sharply defined graduations on the protractor are easy to read, helping to minimize visual errors. This pack of 12 protractors ensures that there are plenty to go around in the classroom or at home.