The ADE 651 is manufactured by a British company, which was recently shut down by the British government, pending a massive fraud investigation. Are you surprised? (I'm only surprised that the government actually took action, considering some of the crackpot things I have seen for sale.)
The ADE 651 follows standard dowsing rod form and behavior. Wikipedia describes it as being "a swiveling antenna mounted via hinge to a plastic handgrip." The ADE 651 detects a number of different substances, from truffles to contraband ivory.