The test results of lead and silver should be exchanged batch by batch. The certificate of exchange inspection shall be issued by an independent international inspection agency or CIQ (Entry-Exit Inspection and Quarantine Bureau) /CCIC (China Commodity Inspection Bureau). At that time, the buyer and the seller shall exchange the test results in a normal commercial way on the date agreed in advance, but in any case, it shall be completed within 60 calendar days after the final receipt of the samples. The buyer and the seller promise to agree on the date of exchanging test results as soon as possible.