This is a 1/4" BSP pneumatic filter regulator and lubricator combo unit for air compressor systems. [1]
Air Treatment: This unit includes a filter to remove contaminants and moisture from compressed air, as well as a lubricator to add oil mist for pneumatic tool lubrication.
Pressure Control: A built-in pressure regulator with a gauge allows you to manage and maintain a consistent output pressure for your tools.
Specifications: It is typically designed for maximum working pressures around 10 bar (150 psi) and fits 1/4" or 1/2" port sizes depending on the specific model. [1, 2, 3, 4, 5]