Brewery & distillery grain mills are roller mills, usually with 2-4 rollers. Using roller mills (as opposed to hammer mills) preserves grain husks, minimizes dust, and bypasses the maintenance of screens. ... Click Here to see table with corresponding model images. System Size. RAD 2-Roller. RAD 4-Roller. RMS 2-Roller. RMS 4-Roller. 3-10 BBL. 6 ...