... , through the right and left self-governed spring as well, with two straight needles, self-lubricating vertical-axis rotating hook for ... lockstitch, serve for the purpose of sewing shirts, uniforms, jeans, overcoats, etc. applied to a wide range of sewing materials, synchronized feed by needle ... /4"57-1333.43500650*320*67050/52 DY-842A-003 high-speed double needle lockstitch sewing machine