Final answer:
Solidworks Toolbox is the Solidworks add-in that has fasteners already created.
Step-by-step explanation:
The Solidworks add-in that has fasteners already created is Solidworks Toolbox.
Solidworks Toolbox is a powerful library of standard parts and fasteners that can be used in Solidworks to quickly create assemblies and designs. It contains a wide range of pre-designed fasteners such as screws, bolts, nuts, washers, and more, making it easier and faster to add them to your Solidworks projects.
By using Solidworks Toolbox, you can avoid the need to manually create or search for individual fasteners, saving time and reducing the chances of errors.