What kind of material is Su Xinhao's middle finger?

Video uploaded by users in Weibo. Su Xinhao came from the third generation army in Feng Jun. On February 7th, 65438, a video uploaded by a Weibo user showed that Su Xinhao and his teammates were playing werewolf killing. Su Xinhao should have lost the game and put up his middle finger. Su Xinhao, male, was born on June 65438+1October 65438+February, 2007. He is an artist in Feng Jun of Jinghua Times and a trainee of TF family.