Suggested Retail:$22. CHAIR NOT INCLUDED. Gaiam Balance Disc Wobble Cushion Stability Core Trainer for Home or Office Desk Chair & Kids Alternative Classroom Sensory Wiggle Seat- 16 inch diameter. Turn almost any chair or seat into an active one by placing the disc on top to add instability and strengthen your core. This posture-improving inflatable 16" Balance Disc will engage your abs and core muscles while you sit. Great for a meditation seat or wherever you need a little extra cushion. By controlling the firmness of the cushion, you can adapt it to your fitness needs and comfort-ability. Can also be used for strengthening exercises in or out of your chair. 7 DAY FULL REFUND GUARANTEE ON THIS ITEM IF ANY ISSUE IS FOUND THAT WAS NOT DESCRIBED/PICTURED. PAID DELIVERY AND 7 DAY ALTERNATE PICK-UP ALSO AVAILABLE. SEE NOTES TO BIDDER, IN AUCTION DETAILS, AT THE TOP OF PAGE 1 FOR MORE INFO.