Correct, Midge.
These things should come with a warning. I'd be dubious about using one in front of a spectator with a pacemaker, too
They ARE remarkably strong for their physical size, and I remember using a 'brick' sized equivalent a few years back to get the same effects.
The high price puts a lot of people off the Micro 5 PK kit, but you really DO get a lot for your money. Especially the shim wire, etc. which enables you to gaff your own cards, coins and the like.
There's everything in the kit to get you off to a running start, and with a little imagination, you'll be pouring out tricks of your own quite quickly.