Invoices will be rendered with each shipment and discount privilege will apply from the later of date of scheduled delivery, receipt of goods or date of invoice. Seller shall maintain for a period of three (3) years after final payment under this purchase order, all records and accounts pertaining to work performed or goods supplied by Seller. Buyer shall have the right to audit, copy and inspect or cause to have audited, copied and inspected such records and account to all reasonable times during the course of such work or supply and for the above three (3) year period for the purpose of verifying Seller’s invoices and its compliance with this purchase order.