Feature: 1. Principle of optical imaging: Lens imaging is not a projection, but observation through a lens, you can see the image on the canvas. 2. Material: Optical coated polymethyl methacrylate lens ABS plastic, durable. 3. Support for mobile phones and tablets - you need to download the optical drawing application, put the phone on the shelf, and then you can start drawing without the need for drawing skills. 4. Education: Help develop hand-eye coordination and basic drawing skills.