The Kalson 103 is an industrial-grade, cast iron sewing machine (model number TA-1 103-K) with a maximum speed of 4,000–5,000 stitches per minute and a stitch length of 2–5 mm. It is designed for sewing heavy-duty fabrics like cotton, linen, denim, and synthetics. Features include a traditional shuttle for easy maintenance, a lever-type stitch regulator, and an auto-tripping bobbin winder.