An air lubricator provides needed lubrication to moving components in a pneumatic tool.
Without lubrication, most air tools will quickly stop working and likely take damage.
However, most modern pneumatic systems are self-lubricating, meaning they don't require an individual lubricating unit.
Therefore, it is important to know the system and component requirements to see if an individual lubricating unit is needed.
A pneumatic system can use just a compressed air lubricator or a lubricator that is part of a filter, regulator, lubricator (FRL) unit.