This model adopts ball wheel and Needle bearing, matching the connecting rod type, to reduce friction and to avoid maintenance; Shuttle switch of Full-rotation and uprightness used; A security for a device to operate, greatly reducing the large flame damage; When spongy material is sewn, it will not transform; instead, it shall be sewn very smoothly and neatly. Not wrinkling when sewing thin materials. With pleasing outline when sewing thick materials. Suitable for sewing shoes and leather goods etc which need high quality sewing.