In the WooCommerce Product Add-Ons Ultimate plugin select fields allow you to add select fields to your WooCommerce product. Select fields allows the user to make a single choice from a list of options. There’s a demo product here.

To add a select field, just choose ‘Select’ from the ‘Field Type’ dropdown list.

When you choose ‘Select’ as the field type, the ‘Options’ tab will appear. Click this to add your options.

Click the ‘Add Option’ button to add your first option then enter the option name in the first field, under ‘Label’. You can also assign a price to this option that will only be added to the product price if the user selects this option.
First field is instruction only
Select this option if the first option in the select field is an instruction – e.g. ‘Pick an option’.
Dynamically populate options in select fields
If you have a lot of options, it may be easier to populate their values dynamically. There are several different methods for doing this – either programmatically or through patterns. See this article for more information.