[. . . ] [. . . ] Be sure to read and follow all the instructions contained in the manual and this addendum, and keep them in a safe place for future reference. 400RB-IV Ventilation information for the 400RB-IV: Page 9: Installation: Installation and Maintenance For combos, make sure there is three feet of clearance around the sides, top, back and front of the unit for proper ventilation. The 400RB-IV head requires at least 1 3/4 inches (one rack space) of clearance above for proper ventilation. 400RB-IV Owners Manual Addendum Part #: 160-0004-C Printed in the U. S. A. [. . . ] [. . . ]