How does a scintillation counter work?

A scintillation counter measures ionizing radiation. The sensor, called a scintillator, consists of a transparent crystal, usually phosphor, plastic (usually containing anthracene), or organic liquid...

Geiger counters have gas in them that does not normally conduct electricity. When ionizing radiation passes into a Geiger counter, it makes the gas conductive, and the conductivity can be measured,...

Counter-propellers (proper name contra-rotating propellers) work by spinning in opposite directions. This cancels out torque in the same way as a helicopter uses rotors to cancel torque.

These work by picking up electrical signals that are released when the heart muscle cells contract.

Well for one they can negate monster effects, spell and traps. It also has the effect whatever is on the card description