Description: MaterialOptical Experimental Tools are made from pp material, which is durable using. Suitable for lab, school, students experiment PracticalLight source optical physics experiment teaching instruments for Teacher are in a simple design, but very useful and practical Excellent ExperienceThe perfect scientific apparatus workmanship threeline light source will give you an excellent use experience GiftThree- way Semiconductor is not a physics teaching experimental equipment, but also a gift for children to detect scientifically Great EquipmentPhysical Teaching Instruments are great equipment for students to learn the principle of the light reflection Specification: Material: PP Size Chart: 10.5cmx7cm/4.13inchx2.76inch Package Includes: 1 threeline light source Note: 1.This is not infant toy, please take away from children to avoid eating. 2.Please allow slightly errors due to manual measurement and different monitors.