This rocket knife can cut through anything like butter.
The knife was invented by David Windestal, a Swedish YouTuber who loves to do crazy experiments like this one. Windestal was inspired by a "Mythbusters" episode that showed a car getting cut in half by a quick-moving blade.
Since then, he's been experimenting, cutting through drones, helmets, and other hard-to-cut objects, with a knife that can travel up to 125 mph.
