the letter of credit shall be available for drawing by seller on the final settlement when all details relating to final weight,price and quality are known, against presentation of seller's final invoice.这个说的是信用证的付款环节：当所有有关最终重量，价格和质量的细节都已标明，且卖方出示了最终的商业发票以后，卖方应当可以使用信用证来取得款项。drawing 信用证条款中的专门表述，取款，款项取得。
