Literally, the $US40,000 (apiece) devices did absolutely nothing. Nada. Zilch. Experts think the insides contained nothing more than a dumb RFID card. Powered by nothing. Nope, not even a power supply. Just some snake oil, if that. $US85 million!
Even worse, "inventor" McCormick was a firm, open believer in dowsing (as in, finding water with a stick), and that's what the device was based on. Dowsing!
The BBC ran an investigative report on the device, during which McCormick claimed, without breaking his stride, that the device could detect explosives up to one kilometre away. Video below (money shot at 7:30 when the insides are shown to be empty):
Now the money lost is bad, but the loss of life is worse. Immeasurable. Security personnel and Iraqi soldiers were using these powerless dowsing rod devices in the field to detect bombs at security checkpoints and who knows where else. Scores died with this murderous thing gripped tightly in their hands. Hundreds more when the security checkpoints, armed with these devices, failed to protect them. [BBC, CrunchGear]