I have to use a pen at work outside in both frigid and wet weather. I use a black, fine line Fisher Space Pen in this model. It is very handy because you do not need 2 hands to remove the cap, I have lost a few but the only time I broke one was when I drove over it with my truck. That pen still works but the refill no longer "clicks" in and out, so I keep it it the truck to fill out the diary.

Mike