This seat add-on is made of marble balls and good nylon wires. It is a long lasting product suitable for use on fabric and leather seats anti-slip backing with adjustable strap. Allows circulation of air this product is a universal model, it will fit to any car. Gives you very comfortable journey and will reduce the human body heat while driving long distance. Gives relief to your back body and it is like a acupuncture treatment, this will avoid the medical problem like piles, body heat, blood pressure. Also it gives both stylish look to car interiors and comfort for front seat passengers. For use in car, office, home etc. Promote blood circulation massages back, waist, backbone, thighs etc. Can relieve fatigue, muscle tension, pressure and gives you vigor quickly.