Bundles allow you to package items together into a kit that will allow you to easily add multiple items to a project at once. You can bundle items that are typically sold together to speed up your project creation.
To create a bundle, open your project and go to the Builder tab, then click Edit Items at the bottom of the line item list.
Select the items that you would like to bundle together, and click Create Bundle.
This will bring up a window that allows you to customize the bundle.
Give the bundle a name and a short description.
Set default quantities for each item using the fields to the right of each item name.
Click Save.
This will bundle those items in your project.
You can also choose to save the bundle to your database by clicking Save The Bundle To My Database For Future Use in the "Create Bundle" window.
The next time you search for this bundle in any project, it will appear in blue at the top of your product search.
Here is a video tutorial on creating Item Bundles.