The size of Tianzhu is about 3.8cm in length and 1.4cm in width. As it is a natural agate, the length and thickness of each bead are generally different, with a difference of about 2 millimeters. Nine eyed Tianzhu, nine eyes are made artificially. The Tianzhu necklace is made of agate material, which may have minor flaws and each Tianzhu has a slight difference in size. It requires careful and perfect shooting.