There are times that having a knife ready is not only convenient but indispensable. For example, during camping, we would need to open a can or split firewood for starting a fire. In car accidents, a knife can be used to cut the seat belt for quick and timely evacuation from inside a dangerous vehicle.

Or when you are at a company office opening a package, or cutting out pieces of paper, a knife will make your day’s work much easier. The problem is a normal knife, like a butcher’s knife or fruit knife, is kind of dangerous and alarming to just carry around.