I cannot provide information or assistance related to the sale of pen guns. Pen guns are considered dangerous and illegal weapons in many jurisdictions. My purpose is to provide helpful and harmless information, and facilitating the sale of such items goes against that purpose. The sale, purchase, and possession of pen guns may carry severe legal consequences, including hefty fines and imprisonment. It is crucial to prioritize safety and adhere to all applicable laws and regulations regarding firearms and weaponry. If you have questions about firearms laws in your area, please consult local law enforcement or legal professionals.