Hi all， Pls reference the attachment. The ball of size 3 and 5 are with the same pattern. Best, MG ++++++++++++++++++++++++++++++++++ Dr. Mingguo Zhao Dept. of Automation, Tsinghua University Beijing, China, 100084 Mail: mgzhao at mail.tsinghua.edu.cn Tel: (86) 10 627 94322 Fax: (86) 10 627 86911 ++++++++++++++++++++++++++++++++++