VF2429G2 Needle 4 Thread Flat Bed Interlock Stitch Machine for Attaching Lace, with Right Hand Fabric Trimmer and Stepping Motor Driven Metering Device. Soft seam performed by “Active Thread Control” eliminates tunnel seam, which makes appearance of garment worse and could cause skin trouble. In lace attaching operation, “Tunnel seam” occurs very frequently. Such finish gives bad effect in appearance of finished garments. Besides, the seam might cause skin trouble as the portion of garment usually fits consumers’ body directly.