First of all, the pattern in the upper left corner of packaging, genuine products and anti-counterfeiting labels will change to different colors of blue and green with the change of viewing angle. Then you uncover the anti-counterfeiting label, get the anti-counterfeiting number of 18 digits, and then log in to www.YST.COM.CN to check the authenticity. Or send a text message to 106695882 10886 to check the authenticity!