Before being shipped, they are tested again and marked with a unique code or mark, because in case of replacement, we can trace our item with certainty. PLEASE NOTE UPON RECEIPT OF THE GOODS, IMMEDIATELY CHECK THAT EVERYTHING IS IN ORDER AND THAT THERE IS NO DAMAGE. ALWAYS ACCEPT THE PACKAGE BY SIGNING WITH RESERVE OF CONTROL FOR PACKAGING ANOMALY. PAYMENT MUST BE MADE WITHIN 4 DAYS OF PURCHASING THE ITEM, AFTER THIS DATE, A DISPUTE REGARDING UNPAID ITEM WILL BE OPENED.