Grace Speed Control Box For Quilting Sewing Machine (Viking Mega Quilter) Speed dial that allows you to set your machine to desired stitch speed. On/Off button to start and stop your machine. Easy to use knob controls stitching speed. Pulse Button machine runs until you release it, or touch and release for a single stitch. Set of four bungee clamps. Fourth rail for batting. If a machine is not on this list, it may not work with Grace King.