WASP CO2 injection knife
Wasp injection knife blade CO2 dive water shark 1


This knife injects CO2 in an attempt to expand and freeze a wound cavity.

A few of these unconventional knife designs have utilized compressed gas. Ballistic knives, for example, have used compressed air or CO2 to fire a blade a short distance from the handle. Outside video games and movies, the effectiveness of ballistic knives is dubious to say the least. But there’s a second type of knife that uses compressed gas — the injection knife.


Wasp injection knife blade CO2 dive water shark 2

It is designed to inject high-pressure gas into a wound cavity through a hole in the blade, rather than using gas to propel the blade forward. This is said to expand and freeze the wound, inflicting more damage to the target. On Wasp Injection, the knife’s manufacturer states:

“This weapon injects a freezing cold ball of compressed gas, approximately the size of a basketball, at 800psi nearly instantly. The effects of this injection will drop many of the world’s largest land predators. The effects of the compressed gas not only cause over-inflation during ascent when used underwater, but also freezes all tissues and organs surrounding the point of injection on land or at sea.”

Wasp injection knife blade CO2 dive water shark 3

These are some bold claims, but how does the knife’s injection system fare in reality? Unsurprisingly, there doesn’t appear to be any video footage of SCUBA divers stabbing sharks with the WASP, but several YouTubers have tested the knife on ballistic gel, plastic bottles, and watermelons to show how the system works:



 One downside to this knife is that it can only inject CO2 once before the handle must be unscrewed and a new cartridge must be installed. Also, it’ll set you back $500 for standard models, or $600 for the larger WASP Bowie model.

So, what do you think of this unconventional injection knife? Tell us your opinion in the comments below.