P-38 ( Small )
Don't let it's small size and low price fool you. These handy P-38 can openers were issued by the U.S. military for decades. Growing up, these were always popular with Boy Scouts and travelers. These are brand new, nice and shiny. We have opened giant #10 industrial cans with them. It's not the fastest can opener you have ever used but we feel confident saying, it's probably the smallest.
A Trivia Note: The P-38 Can opener got its name because it took 38 movements to open a standard military C-Rations can. Having canned food for an emergency does you no good if you can't get in to it.