definiens: means gross invoiced sales by [COMPANY] or its Affiliates, or [COMPANY] or its Affiliates, as the case may be, less : ( a ) non - commercial sales, such as transactions among Af filiates of either Party, or sales for pre - clinical or clinical trials or other testing ; ( b ) sales by [COMPANY] to Commission - Free Practitioners or hospitals or clinics at which a Commission -Free Practitioner has privileges to implant Devices ; ( c ) sales, use, value added, occupation or excise taxes, and other taxes based or imposed on the transfer of a product fro m one party to another or the provision of a servic e ; ( d ) freight, duty or insurance ; and ( e ) rebates, refunds, exchanges, discounts and allowanc es and credits for the foregoing and net of amounts written off by either of [COMPANY] or Neuro logix as uncollectible