A 3d printing pen is a simple handheld 3d printer. You can use PLA or ABS filament as printing material (diameter 1.75 mm).To use ABS material, the nozzle temperature is usually 210-250 degree. But it can be 70-120 degree (even 70-80 degree) to use PLA material. So for safety, it is best to use PLA filament. It is a good gift for kids or adults who are over 8 years old.