The BellMouthRound sheet in the HVAC.xls workbook defines the round bell mouths that you want in the Catalog.
PartNumber
Type the part number for the object. An example is Round Bellmouth 300x250.
PartDescription
Type a description for the object.
FaceWidth
Type the face width for the object.
FaceDepth
Type the face depth for the object.
ComponentType
Type the component type for the elbow.
SymbolDefinition
Type the symbol definition for the object.