From Jun.01st,2013, because china register mail rising the price, so if you choose flat post without tracking No, I will ship them by HK flat post and without tracking No.

Free shipping cargo:
1, HK register mail track website is :
http://www.hongkongpost.hk/eng/index.htm

2, China register mail track website is :
http://intmail.183.com.cn/itemstatus_en.jsp
or
http://www.17track.net/index.shtml