I feel the need to inquire about the 'tactical pen'. Amazon has a page of them.
Like allenr said but didn't say is that if your attacker misses you with 18 rounds from his 9 mm handgun then your knife will come in handy and could be very lethal against your attacker.
I believe every word of that. It seems to me that a tactical pen, at least for those of us not thoroughly trained in hand to hand, is a 'concealed in plain sight' weapon intended to allow close approach. Since it can only stab, it needs to be stabbed into an eye and on into the brain, or into the solar plexus and up to perforate the diaphragm - which is probably not soon enough disabling.The problem with s a tactical pen is that it is designed as a stabbing weapon. A trained knife fighter knows that stabbing is the least effective use of the knife. It will not penetrate ribs. If it slides between ribs unless it is long it will not reach a vital organ or artery.
You are better off with a very sharp folding knife because the best use of the knife is to slash. A slash can cut either carotid artery, deliver a psychologically alarming wound, blind a person, and cut a windpipe. And a 3.5 inch blade can do all that if used properly.