What Does B-Stock Mean? These items may have been opened, and then returned to us gently used, may be a brand new item with a cosmetic flaw ("factory second"), or may have been used as a demo unit. B-Stock items are guaranteed to function as they should and come with our 25-year warranty. All B-stock items can be returned for a refund within 30 days of shipment if returned in the same condition as received.