definiens: shall mean, with respect to any Pr oduct, the gross sales price for such Product invoiced by Surface, its Licensees or their respect i ve Affiliates to customers who are not Affiliates ( or are Affiliates but are the end users of such Product ), less ( a ) cr edits, allowances, discounts and rebates to, and ch argebacks from the account of, such customers ; ( b ) freight and ins urance costs in transporting such Product to the ex tent separately invoiced and included in the gross sales price ; ( c ) cash, quantity and trade discounts, rebates and ot her price reductions for such Product ; ( d ) sales, use, value- added and other direct taxes for such Product to th e extent separately invoiced and included in the gross sales price ; ( e ) customs duties, tariffs, surcharges and other governmental charges incurred in exporting or impor ting such Product to the extent separately invoiced and included in the gross sales price ; and ( f ) an allow ance for uncollectible or bad debts for such Produc t determined in accordance with generally accepted accounting pr inciples not to exceed 3 % of Net Sales of such Prod uct for the applicable quarterly reporting period before giving effect to this subsection ( f )