The loaner function allows you to assign a loaner to a customer for whatever reason (their unit in service, etc.).
When a loaner is loaded to a customer, a loaner button will be displayed when you pull them up under payments. If the loaner is overdue it will be red. To view the loaner info you can click on the loaner button on the payment screen.
Loaner contracts are closed the same as a regular rent to own contract, from Contract Close (Point of Sale Menu option 4 then option 1).
The due date on loaners can be changed by clicking on the "Has Loaner" button from the payment screen, then changing the due date field.