Schmetz Stretch Needles are made especially for synthetic suede or highly elastic synthetic knit wear. This needle is constructed with a medium ball point to help prevent skipped stitches. Two needles mounted on one shaft, used to create two rows of stitching at the same time. Use two spools of thread and pass each thread on a different side of the tension discs and thread one thread one into each needle. Only one bobbin thread is used and the stitches create a double web of stitches on the back. Must use with a zigzag stitch plate. 4 mm, Size 75. 1 pc.