Pumped disk for balancing Thorn Fit Air Pad pump Thorn sensory disc will allow you to work effectively on the correct body posture. Inflated disk with studs offer versatile application during corrective and rehabilitation classes. Recommended for people spending a lot of time in a sitting position.  Technical data:· Diameter: 33 cm· Pop attached to the product· Smooth surface on the top layer· Rubbed surface on the bottom· Versatile device for exercising ró wnew· Example exercises illustrated on the back of box