Come and see our amazing products. Plug the adapter into the back of the pen and choose your filament. The red light will turn on indicating warm up, this will take about 2-3 mins. Double click the forward button to start and feed the filament through the back of the pen. Once the filament has reached the nozzle of the pen, click forward to stop. Press and hold the forward button or double click for a continous flow. Once you have completed your design, press and hold the reverse button to retract filament. Pls confirm further with us if any query about packing info, inventory status and time schedule.