Exertools is the exclusive manufacturer of the DynaDisc
you can sit on it, lay on it, or stand on it -- great for hobbies requiring extended sitting like sewing, quilters, fishing, hunting
one of the best core stabilization products on the market
use it at home, in the office, at the gym, or in physical therapy
Free -- DynaDisc exercise guide
The DYNADISC™ balance cushion has become a staple in training & exercise rooms across the country. The DYNA DISC™ works your core muscles more completely than a gymball because it focuses on those muscles no matter what position you are in. Use it at home and then take it with you to the gym. Slip it into your suitcase when you travel so that you can have a core workout in the hotel room.
Dyna Disc Balance Cushion - Royal Blue - B00077E32C