Products like "spare air" cost approx $300
but: (US TSA example)
"A compressed gas cylinder is allowed in carry-on or checked baggage ONLY if the regulator valve is completely disconnected from the cylinder and the cylinder is no longer sealed (i.e. the cylinder has an open end). The cylinder must have an opening to allow for a visual inspection inside. TSA Security Screeners will NOT remove the seal/regulator valve from the cylinder at the checkpoint. If the cylinder is sealed (i.e. the regulator valve is still attached), the cylinder is prohibited and not permitted through the security checkpoint, regardless of the reading on the pressure gauge indicator. TSA Security Screeners must visibly ensure that the cylinder is completely empty and that there are no prohibited items inside."
According to my (limited) knowledge certified FAA/EASA (aviation) spare air device not exist... hope someone can correct that statement
