High Quality: Made of acrylic material, clear acrylic resists shattering and impact, good light transmittance, shape is not easy to change, can be used for a long time. Size: Physics optical lens: 6x1.5x1cm, , double convex: 6x1.5x1cm, double concave: 6x1.7x0.95cm, rectangle: 6.05x3x0.95cm, semicircle: 5.95x3x0.95cm. Function: A great set for demonstrating optical principles and effects for students and learning about the properties of light. Nice set for reflecting and refracting. Application: Excellent for physics classrooms. Ideal for a variety of experiments in optics, light refraction, spectrometry and wavelengths. Package Include: 5 Pieces different style prism and lens set, Set includes: physics optical lens, double concave, double convex, rectangle, semicircle, which can show the refraction of light on different objects.