This device is an oriental sex aid consisting of a set of two metal balls (one solid and one partially filled with mercury). Although these are often used in an activity with a partner this sex aid is usually used by women on their own.
- The solid ball is placed in the vagina near the cervix
- The ball partially filled with mercury is also placed in the vagina near the first one. When any movement causes the mercury filled ball to hit the deeper one, vibrations are spread throughout the vaginal area.