TOGU Dynair Senso Ball Cushion Balance Disc - Inflated Fitness Disc for Core Exercise, Balance Pad for Office Chair &ndash; Helps with Posture & Improve Workouts With one smooth side and one side covered in Senso knobs, the Dynair Cushion can be used as a balance disc for exercise, as a seat cushion, or as a massage tool Great for adding instability and engaging muscles during pushups, crunches, standing balance activities and other exercises Supports proper posture when used as a seat cushion Textured Senso knobs stimulate skin and promote blood flow when used as a massager So without spending time for any additional exercises, the back muscles can easily be trained at the office or at home