# Assembly Import
Multiple file assembly model, you can package all model files into a zip file, and make the zip file name consistent with the top assembly file name, the default conversion of the top assembly after uploading.
If the assembly is inconsistent at level 2, the user needs to manually select the document that needs to be converted.
When importing an assembly in intermediate format, the option "Do you want to merge the assembly?" will be prompted:

- The missing parts in the import assembly can be specified manually by right-clicking the menu:
Right-click a missing part in the feature panel to choose to specify the part or remove it.

Select the specified part from the menu and the "Specify Part" dialog box will pop up.

- If there is a document with the same name as the missing part within the current project, the part or assembly with the same name within the current project is selected by default.
- If there is no part with the same name, the part or assembly of the current project is displayed by default. If the missing part is an assembly, the assembly of the current project is displayed by default.
The "Show Preview" function makes the preview of the selected part appear in the location of the missing part in the viewport. This item is not checked by default.
Select the part and click OK. The missing part will be replaced by the selected part.