1、3 Colors: This 3D printed pen set includes 3 colors of PLA plastic to meet your needs and shipping in random colors.2、Red Lighting Preheating: Plug the adapter into the back of the 3D printing pen and select your filament. The red lighting will come on to indicate warm up, this will take about 2 to 3 minutes.3、How to Operate: Double click the forward button to start and pass the filament through the back of the pen. Once the filament reaches the tip of the pen, click forward to stop. Press and hold the forward button or double click to get a continuous stream. Once you have completed your design, press and hold the reverse button to retract the filament.4、Stepless Speed Control: Our 3D printing pen also has a stepless speed control function, designed for optimal speed control, whether its a slower project or a faster fill job, this pen can handle it all.5、Promote Ability: This 3D printing pen can be kept at home to promote spatial thinking, imagination and artistic skills in your family and children.6、Usage Scenarios: This 3D printing pen can be applied to family and child interaction, as a practical tool for making handmade gifts or decorations, or for daily repairs at home.