The machine is equipped with a hook-driving shaft-offset mechanism which places the hook-rotating shaft off-center from the center of zigzg stroke of the needle.This mechnism allows the blade point of the hook to catch the needle thread every time regardless of the needle throwing direction.As a result,this machine is immune to sewing troubles,such as stitch skipping and thread breakage.annoyances likely to occur with the conventional machine.especially when the needle throws to the right.HM2280N/2284N can be used for lockstitch,zigzag stitch,two point and four point zigzag stitch,and according to the different shaft-offset mechansim.you can have more than 11 kinds patterns.