1. Professional Used to form a 3 thread overlock chain stitch on light and thin fabrics, providing a firm and stable edge that prevents fabric from loosening. The covered chain stitch offers greater elasticity, making it suitable for sewing underwear that needs to expand and recover when worn. 2. Adjustable stitch length 1.5 3 mm and overlock width 3 4 mm to meet different edge sealing needs. Stitch tension adjustment design ensures uniform thread tension and stable thread force during sewing, helping prevent fabric from stretching. 3. Material Cast iron technology and surface baking technology provide wear resistance and rust resistance, with precise and powerful performance. Fixed presser foot and nut type needle chuck prevent stitches from skipping and help maintain a stable, beautiful stitch track. 4. Application Designed for overlock seaming of multi layer fabrics such as silk, linen, cotton, wool, chemical fiber, etc., or for reinforcement of single layer 3 or 4 line edges. Enables quick and easy seam creation.