THIS UNIQUE THREAD CUTTER IS MOUNTED ONTO THE PRESSER FOOT BAR OF YOUR MACHINE, FACING TOWARDS THE BACK (AS SEEN IN THE SECOND PHOTO). ONCE YOU ARE FINISHED WITH A CERTAIN PORTION OF YOUR PROJECT, YOU MAY SIMPLY PULL THE THREAD BEHIND THE FOOT AND INTO THE SPIRAL SPRING PART AND PULL BACK FORWARD. THIS WILL GIVE A CLEAN CUT TO YOUR THREAD AND TAKE AWAY THE NEED FOR THE USE OF NIPPERS WHILE SEWING!!! NO EXTRA HAND NEEDED!!!