... width:12mm 3.low noise,high efficiency. Cam controled extra heavy duty long arm zigzag machine with large barrel shuttle hook and ... cams, suitable for straight stitch, 2 step, 3 step,and 4 step zigzag, pneumatic presser foot lift and pneumatic back tack ... items. A high foot lifter up to 20mm allows for heavy & bulky materials, such as sail, tent & marquees and tarpaulins.This ...