With Lightspeed Multi-Store you can look up the availability of products in your other stores.
OnSite 3.8 and later
To view a product’s availability in another store, in the list of products click the down arrow next to the availability of the product. A list of all store locations is displayed. Select the location you want to search. The product’s availability in the selected store is displayed.
Onsite 3.0 - 3.6.8
To find a product in another store, click the This Store bubble that appears when you're in the POS screen or the Preview Pane of the Browser. Click the Inventory bubble and from the Inventory statuses click the location you want to search.