If you need return and replacement because of quality problems, first,you should test the product and provide the testing report . After it's proved , we would accept your return or replacment . And then you would be given a full refund .(Please Note:we will not refund if the product is used or the packing is damaged .) secondly , you should fill in the relevant approval form about return and replacement . Or you can contact us to get refund and replacement approval number . If you need further information or have questions about the return of some specific products , please fill in customer service form and contact with our CSR .