This 4-wheel ab roller, though simple in looks, benefits your body in some amazing ways. It will help strengthen and tone your abdominal muscles and also help strengthen the lower back. It not only works your core and lower back, but also works and strengthens your shoulder muscles, chest, and arms. A strong core helps you perform a long list of daily movements with greater ease and a reduced risk of injury. The 4-wheel design ensures smooth, consistent, and fluid motion. It does not wobble as the 4 wheels distribute the weight equally on them while you train and exercise.