>>840169I think it's a little thicker than a pen, but I guess it's in the same ballpark. Seems great for what it is, a part of me wishes I bought the TK75 with an extender now that I looked it up. Seems ideal for outdoors use, the PD35 is probably the more sensible general purpose light though.
https://www.youtube.com/watch?v=jazPTN44sH0