The pelvic base exercise balls called Mediballs secret consist of a silicone material and are used for medical training purposes. Their ergonomic design simplifies insertion and removal, while the attached return strap is concealed inside the body to ensure particular discretion. Thanks to the balls’ innovative structure, they are extremely silent. Located inside each ball is a weight that oscillates back in forth when the body is in motion, thus constantly triggering new stimulation impulses.