2pcs High Voltage Generator DC 3v-6v to 400kV 400000V Boost Step-up Power Module High Voltage Transformer

These work perfectly. At 5V they draw about 1-2A and will arc about 1-1.25”. That suggests that they are more like 200,000V, but still loud and very cool. Trivially easy to use and wire up. Cannot speak to durability, but so far, they haven’t fried.

I am getting a 1 inch or better arch with 12 Volts. The sound this thing makes will scare intruders away!

Very potent. Works as advertised

So me and a buddy are enrolled in an electrician course, and we might👀 have used these and some 9v batteries to build a taser (don’t worry we knew what we were doing). I will say that these things are really strong, we ran WAY too much current through them and they’re still working fine. It was a great project, super fun, and honestly made us jump when we first started it up.

It's got a nice loud pop. I discovered that making the contact tips bigger around and adding a capisitor. No I don't have anyone to test it on. Hmm I might have to try it on myself.

What useless fun is this?!

Low quality, worked only for few minutes. The only positive is it does gives high voltage, although for very short time

It works, and produces a nice spark (powered with 4 AA batteries), but that spark won't jump across more that about a 1/4 inch gap. There is no way this device produces a 400KV output, its more like around 20KV. I won't return it because Its cheap enough to keep and play around with. But, buyer beware, the seller is giving very inaccurate specs about this product.

i made something amazing with these and theyre fantastic

Running off a 3.7V Lion and tested the output voltage with a meter specifically designed for high voltages (electric cattle fences). Doesn't come anywhere near 400,000. It could barely reach 4000. So yeah, not quite as advertised.