The 600/5600 series transfer grilles are designed to ensure visual privacy while providing air circulation from one area to another. The 600/5600 provides a single side mounting frame for use where appearance is an issue on only one side, as in a utility or storage closet. The 600A/5600A provides a double sided mounting frame to fit varying door thickness, where a finished look is required on both sides, as in an office or kitchen door. The 600C is a core only unit useful in applications where a frame is not desired. The sight–proof blade configuration and unobtrusive appearance make Krueger’s 600/5600 series grille an ideal choice for wall or door air transfer from room to room.