Hello, thank you very much for choosing the products of Nanjing Oulu Electrical. Our maintenance department's phone number is 025-57506668, extension 836. Address: No. 95, Xinggangwan Road, Liuhe Economic Development Zone, Nanjing City.When sending for repair, please attach a note stating the malfunction of the product and your contact information.Upon receipt, we will provide feedback on the test results and offer a quotation as soon as possible. Thank you again for your trust and support!