Feed-up-the-arm Interlock Stitch Machine All rounder has strong functions such as standing seam sewing, reverse seam sewing, collar sewing and pleated sewing, etc. By pressing the button, it can have infinitely variable regulation on needle pith. Simply operate the external regulation bar and the differential ratio can be regulated. With a machine, it can excellently perform the sewing requirements from thin to thick material and all the processes.