These Exair brass high velocity and adjustable air jets utilise the coanda effect (wall attachment of a high velocity fluid) to produce air motion in their surroundings.
A small amount of compressed air is throttled through an internal ring nozzle above sonic velocity.
A vacuum is produced, pulling large volumes of surrounding "free" air, through the jet.
Both the outlet and inlet can be ducted for remote positioning.
If the end is blocked, flow simply reverses at well below OSHA dead ended pressure requirements.