Buttonholing for ordinary cloth,knit,etc.It s suitable for all lightand medium weight materials.High sewing speed and adjustablebutton hole length.With auto lubrication device system and autotrimmer device with auto detected device to the broken thread toavoid the damage of material wh e n the thread broken.Appropriation of 782D in various knit fabric clothing 783D invarious woolen sweater,798D by synchronous belt,work with lownoise,and more stability.