The black ARO pressure regulator is found on the DB225, DB500, and DB800. The DB1500 and DB3000 have a larger regulator, but the maintenance process is the same.
The video below shows the maintenance and cleaning process for this piece.
Purchase a 1 1/4" Pressure Regulator for a DB225 – DB800, manufactured after May 2018
Purchase a 1 1/4" Pressure Regulator for a DB225 – DB800, manufactured prior to May 2018
Purchase a 2" Pressure Regulator for machines manufactured prior to May 2018