... adopts fork feed ,needle movement, link thread take-up, bid hook ,and top and bottom feed to fo For Lockstitch Zigzag ... adopts fork feed ,needle movement, link thread take-up, bid hook ,and top and bottom feed to forms zigzag sewing .It ... and oil increase the working efficiency because of the big rotating hook .Suitable for sewing on leather, canvas and etc. Lockstitch Zigzag ...