Hello. Just to share my experience with you, so that you don't get in trouble with fake xiaomi pistons. I have order one at ebay and after I ordered I have found that there are also FAKE xiaomi pistons available that look very much as original. I was hoping that I will receive original ones, but unfortunately mine was fake. Here is link where you can find comparison fake vs. orignial:
http://bbs.xiaomi.cn/thread-8484817-1-1.html
And below are some pictures of mine fake xiaomi pistons.
http://bbs.xiaomi.cn/thread-8484817-1-1.html
And below are some pictures of mine fake xiaomi pistons.