Set up your stock item variations here.
The drop-down lists are automatically selected from those that have been set up in the Dimensions setup option.
Open: Retail > Merchandise > Merchandise Hierarchy.
Select Variants.
This shows the list of possible varieties, based on the dimensions that you have specified on the Variants tab of the Add New Sub-Class window.
Click Generate.
The newly generated stock items or variants are listed in the Selected variants area of the window.