First ,customers ship us your present samples,then our lab test and analyse them to find the corresponding samples
Comparison :
After test and analyse customer’s samples,then we ship out our corresponding Samples ,no any cost on customer’s side ,The customers test our samples
Retest :
After confirming the quality,clear quantity and price ,then we sigh the contact,we will Arrange PPS to make sure, We will arrange the shipment after customer confirm the PPS
