Place these inflatable seat cushions atop your classroom chairs and secure with the adjustable nylon straps. The slight instability engages user core muscles, working off excess energy for better focus and concentration. Soft PVC cushion contours to students for comfort. An ultra-grippy texture on the bottom of the cushions eliminates distracting slips and slides. Straps adjust to fit chairs up to 19”W. Alter inflation to adjust seat instability. Supports up to 1,100 lb. 14”L x 14”W x 3”H; 3 lb.