The Exercise and Balance Disc This Exercise and Balance Disc is an air-filled cushion for balance and stability training. The upper side of the disc has spiked nubs. This cushion can add a new level of challenge to your workouts, pilates, yoga and rehabilitation. Who is TRAINAHEAD? TRAINAHEAD offers innovative exercise accessories including the newest trends in designs and qualities. Products are eco-friendly made and therefore with no smell. Colours are neutral and design-friendly and the product designs are minimalistic including unique features by most of our products.