The FA4 with electronic foot control is an advanced overlocker with 2 needles and 2, 3 or 4 thread overlock stitching. The differential feed ratio, which is adjustable from 0.5 to 2.25 provides exceptional control for handling all types of fabrics and for creating desired special effects. Threading is a breeze with color-coded thread guides and a self-threading lower looper. Simply lay the thread into the guide, flip a switch, and the lower looper is threaded. The guide is automatically returned to its normal position when you turn the balance wheel. The thread tension automatically release when you lift the presser foot so you can draw through the threads smoothly. The FA4 also lets you quickly switch to rolled hemming without changing the needle plate. A lower looper pre-tension stitch eliminates the need to change tension for rolled hems.