Companion items are a useful way to cross-sell matching items or "mates" such as a sofa chair that is the same style as a sofa.
You can link companion items on the Edit Item modal's Advanced tab:
Companion items appear above an item's Similar Items on your Propcart Pro Webstore and the Propcart Marketplace.
Linking companion item B to item A automatically links item A as a companion to item B.
Note that when linking companion items, the linked item must have one of the public visibilities to be eligible for linking. Companion items are displayed on your webstore (or the Propcart Marketplace), so we don't want private items linked as companions otherwise the buyer won't be able to view it and add it to their set list.