This piece is found on the side of the control box on the DB225, DB500, DB800, DB1500, and DB3000.
Sometimes, glass or dirt can make its way into the moisture trap of the control box filter regulator. This can occur if the machine components are shut down in the wrong order (read about proper startup and shutdown procedures here, to prevent this from happening).
If you need to clean out the moisture trap, watch the video below.
Purchase a replacement 1/4" Control Box Filter Regulator
Cleaning the ARO Pressure Regulator