If you try to create a fitting with more than one size available for the object you are adding, the Multiple Parts Found dialog box prompts you to choose the desired size. If you modify a layout with duct objects, the software zooms to the location where you need to select a substitute part. After you select from the list of available part size names, the original layout is resumed. To turn off this feature, clear Zoom to the object. The software remembers your last preference.