The Perfect Ab-Carver™ Pro will carve your core and help you get ripped abs and sculpted arms. The kinetic “engine” uses a carbon steel spring to turbocharge your abdominal and arm workouts. It provides resistance as you roll out and assistance when you roll back. The ultra-wide tread provides maximum stability when carving left, right and center. Ergonomic hand grips are angled to help activate arm and core muscles. The high-density foam kneepad provides comfort and protection for your knees. The non-bulky design makes it easy for travel and high-quality construction means it is built to last. User weight limit 300 lbs/136kg.