product name: Optical tracking board Material: ABS plastic + acrylic lens Size: 8.0 X 5.3 X 0.0 inches (about 20.3 X 13.9 X 0 Made of optical coating lens and high-quality ABS plastic. The projected image is reflected in the optical lens So that you can track any opaque materials, such as blank paper, handbags, T-shirts Features: optical imaging reproduction, application of wire drawing method Use: put the phone or tablet flat on the table, and place the board on two The board is in the middle, the phone is on one side, and the white paper needed is on the other side. This tracing board set helps develop hand-eye coordination and basic drawing skills without hurting your eyes. Note: Use Before, please tear off the protective film on the surface of the tracing board. It can be used to copy artistic fonts, complex images, baking patterns, etc., and enjoy painting like an artist We will deliver to you in fine and safe packaging. If you have any Questions, please feel free to contact us.