Size: 28 x 17 x 10 cm Purpose - Educational optical demonstration for middle school physics - Demonstrates the law of reflection and the law of refraction of light Setup and operation - Insert the light source into the light source holder - Move the axis on the condenser's image plane - When aligned, the light emitted by the source is the strongest and nearly parallel, enabling the experiment Observation and results - By adjusting the angle between the emitted light and the normal to the demonstration screen, various incidence and reflection phenomena can be observed Key benefits - Clear, hands-on visualization of fundamental optics concepts - Compact and easy to set up for classroom use - Supports standard middle school physics curricula with practical demonstrations Use scenarios - In-class demonstration: A teacher shows how changing the incidence angle affects reflection and refraction, with results observed on the screen - Student-led laboratory activity: Students vary the angle, document the observed phenomena, and relate findings to theoretical principles - Quick warm-up or review: A brief setup to reinforce concepts of reflection and refraction before more complex optics experiments