TSA is becoming sensitive to the crenelated tops of items as weapons, or so I'm told. Thus, if flying put it in the carry-on and then retrieve it. There is a debate whether those little edges actually add anything to the use of the pen or flashlight as a fighting tool.
Folks seem to like the Zebra line of pens for some that are a little less tactical when flying. I've a Zebra in my pocket and a Surefire in my pants. I found, BTW, that the crenelations had tendency to wear a hole in my pants, so I rounded them off. I don't think that lessens them as an impact weapon.
At the old NTI, we had to do a run with available things in the shoot house. I used my Surefire on bright to theoretically blind a dummy and then pound it. Seemed ok to me, but I was told I should have picked up a nearby tennis racket to use - oh, well. I've noted that the so-called nausea producing strobe lights have gone out of style and you don't hear much about them. I sold mine.
While the gun rags were full of stories how they were wonder ray guns, they didn't pan out. I could stare into mine in a mirror, draw and shoot (blue gun Glock). I know one major shooting school that inserted strobes into targets and had students easily just shoot them. That contradicted some fairly well known shills who claimed the strobes totally discombulated them. I once had my daughter look into one - she said - SO WHAT?
In some FOF with strobes - it was a so what, the main problem was low light and not the flashing. That was just annoying. If you were clearing a house (bad idea) and your target was off center from the strobe - the strobe carrier was just a lighthouse to be 'shot'.