Hello! There is a blue label (China Product Quality Electronic Supervision Network) on the back or bottom of each Edifier speaker main box (power amplifier). There is a set of supervision codes on the label. You can send a text message or call 95001111 to check the authenticity. You can also dial 114 to check the supervision code, or log in to www.95001111.com to check the supervision code. in addition. The SN number on the speaker does not have the function of checking authenticity.