The item is an optics experimental equipment, with premium material, durable and portable. It's a demonstrator for the synthesis of three primary colors of light, deepen students' understanding of three primary color light sources. Improve students' practical ability and thinking ability. Features - Color:Black. - Material:Plastic.- Size:11.00X8.50X12.00cm/4.32X3.34X4.72inch.- Battery: 3AA Batteries (Not Included).- Made with premiumquality plastic material, sturdy and durable for long term use.- This color mixing demonstrator is simple to operate and improve the teaching interest.- Visually demonstrate the principle of three primary color to make it easier for students to understand.- Due to the simple operation design make the experiment easier to operate.- Suitable for optical grouping experiment of junior high school physics students. Packing list: 1 x Color Mixing Demonstrator