This is a student grade magnifier made of clear acrylic plastic. It is durable and safe for children because it does not break by dropping on a hard surface. Perfect for science observations such as looking at insects. Also good for demonstrating the function of human eye and camera. This magnifier has 2 lenses. The large lens has a diameter of 45 millimeters, Focal point of 15 centimeters (6 inches) and magnification of 2X. The small lens has a diameter of 17mm, focal point of 60mm and the magnification of 4X.