This is actually a concept piece by Johannes Vogl, which means you can’t really buy one (sorry to dash your hopes). It works exactly as you’d think: when you see or hear a bug, you pick up your flamethrower and trigger it in the general direction of the pest. Being fire, you don’t have to hit it dead on, as bugs are not well-known for withstanding close proximity to open flame.
I have to admit, this isn’t very high-tech. Basically, all he’s done is make a triggering device that incorporates an aerosol can and a lighter, with what appears to be the hand grip and brake mechanism from a ten-speed bike. But what that means is you can easily refill it yourself! It also leaves one hand free, as opposed to the more traditional method of the DIY flamethrower which requires you to hold both the can and your lighter, and risks burning you severely. In addition, it’s more humane for the bugs, as it will instantly incinerate them rather than leaving them to die a slow, painful death from poisoning.
I’m still giggling.
Source: Oh Gizmo!