Ideal for sitting, standing or working out! The Classic Sit Disc is your best bet for a wide range of uses. Incorporate it into your workout to increase instability and up the intensity. It's even strong enough for standing balance exercises - try putting one under each foot for squats. When at your desk, use the Classic Sit Disc as an active sitting cushion to promote proper posture, or put it on the floor to keep your legs and feet active. Available in 13" or 15" disc size.