Automatic Mini In-line Air Tool Oiler with Inlet and Outlet Sizes: 1/4" NPT Lengthen your Air Tools Lifetime and Improve their Performance Provides automatic lubrication of pneumatic air tools which prevents rust and corrosion Allows the tools to have a smoother more effective operation, which extends the tools life. Solid brass construction with high impact clear plastic Automatic Micro-Fog Lubricator: Supplies lubricating oil to pneumatic equipment