With our new Balance Trainer Disc, you can improve balance and stability, tone your entire body, activate muscles and increase strength. Balance Trainer Discs are great for sitting, standing and lying exercises. This disc is made of soft pliable PVC. It can also be used in exercise to provide an unstable surface, forcing you to use more muscles to remain balanced, thus getting a more complete workout. These Balance Trainer Discs are also used by parents and teachers as "wiggle seats" that help active children sit still.When you start using balance disc as a seat cushion, build up your time on it gradually.