3) The sale of the calipers alone
If someone is trying to sell you Brembo's car calipers alone, without the other parts of the braking system, then you are definitely dealing with a fake or with an original equipment part that is being handled incorrectly. In fact, Brembo never markets car calipers separately from the other elements of the kit (that included discs, calipers, adapter brackets and pads).
The counterfeiters, on the other hand, often sell the calipers alone, an option that Brembo's sales programs don't considers. This because selling car calipers separately from the other braking system's components, like the discs or the adapter brackets, must be considered inappropriate.
Therefore, whenever the calipers are sold alone, it's most likely a matter of forgery or anyhow ti's a product lacking all Brembo's guarantees.