... unison feed machanism and double capacity hook. Specifications:This car seat sewing machine is equipped with unison feed machanism ... It is suitable for sewing heavy materials,such as cars seats,sofas, bags,etc. And up to now, it ... is the model which used in sofa and car seat production mostly Speed Motor Needle Stitch Length Height ... ,4P #23 9MM 16MM55KGS 0.1CBM Compound-feed Car Seats Sewing Machine