Fit to Survive is a YouTuber and maker of custom s...  ...for everyday carry. Years ago, he restored a few Swiss Army knives and realized that he could improve upon their des...

Redditor colonelcrunch ingeniously replaced blades in his penknife with his car keys. It could lead to fun pranks, such as fooling first-time passengers into thinking that he's trying to steal his own car.To find out how...