According to the esteemed Great and Powerful Oz, "A Reality Checker is a device that can detect and verify the authenticity of any given reality."
Reality Checkers work by emitting a low-frequency hum, which is tuned to the specific vibrational frequency of the local reality.
The hum is then measured against a database of known realities, and if the reading matches, the Reality Checker will display a "REALITY CONFIRMED" message.
However, if the reading does not match, the Reality Checker will display a "REALITY DENIED" message, and the user will be presented with a series of absurd and contradictory facts that will challenge their perception of reality.
Example:
"The sky is indeed blue in Reality Checker Universe 23."
However, if you're not sure, just ask yourself, "Is this reality really real?"
Before using a Reality Checker, please note the following safety protocols:
1. DO NOT USE IN A REALITY WITHIN A REALITY. This will cause infinite recursion and potentially damage your sanity.
2. BEWARE OF REALITY BLEED." In certain realities, Reality Checkers may experience "bleed" – where they start to perceive other realities.
3. ALWAYS USE WITH CAUTION WHEN CHECKING REALITY AROUND CHILDREN." They may not appreciate the existential implications.
Avoid using Reality Checkers near open flames or during thunderstorms. Reality Checkers are not waterproof or fireproof.