Composer - Importing Products with Variants

1. In Composer click on the Inventory tab in the left hand menu.
2. Click on the Import tab.
3. Select all of the Variants of the product that you want to import using the checkboxes to the left of the product, and then click Import Selected. 
4. In the Import Products dialog box that opens, ensure that Single is selected from the drop down list and click Import Selected.