The sales inventory form lets you add sales items. From the rental/pos screen, you can sell just like you rent, by typing in the item number or scanning the number. The program knows ahead of time if it is a sale item or a rental item. You can also transfer a rental item to a sales item on the fly during a transaction.
Notice you can add subcategories to further categorize your sales inventory. The subcategory names can be changed, or you can choose not to enter subcategories.
There is a much more detailed screen available for those that want to track more info about their costs. (not shown here)