The protractor makes half a circle with a 7 centimeter radius. In the middle of the straight side a 2 centimeter wide semi-circular hole has been made, to easily place the protractor on a line, or combine it with the ruler or a knob. On the round side, there are little indication points per 10 degrees. At each 10 degree point around the edge there is also a small notch, to help you precisely place your pen. Little slots on the top surface indicate the usual 30, 45, 60 and 90 degrees angles.
The protractor has five round holes of 0.5, 1, 1.5, 2 and 2.5 centimeters in diameter, to easily draw circles.