The AMBER™ S | 100 overlock machine has 4, 3, 2 thread capability with 16 different stitches to help you complete any project. Both the left and right front covers open to provide complete access to the looper area, making it super easy to thread. The Differential Feed gives you perfectly even seams - no stretching or distortion on knits or puckering of finer fabrics, and it can also be used for gathering.