1. No bright light, no radiation, no blue light, continuously escorting children's eyes 2. Sensitive pressure sensing, control thickness as you like 3. One-click erase, no eraser needed 4. Built-in button battery, if cleared 100 times a day, a button battery can be used for 365 days 5. Anti-deleting lock key design to keep the baby's wonderful works 6. Size: 30x18 cm 7. Weight: about 137 g